Ah, the 3-golden question...
I'll be simple and honest, most of my points were covered by the rest of the users, so I'll quote a few of them and express myself, while trying not to make a new Twilight book.
Well, here we have the damsel in distress, although if you're facing this thing in battle, you're probably the one in distress. Misdreavus' is on a large number of teams, with good reason since it has all the good qualities of an offensive threat, and also has what it takes to be used defensively. It can fulfill the role of a cleric, spinblocker, setup sweeper, support and it has the ability to beat majority of its checks through the use of a few different moves or a different move-set overall (speaking of which, it uses about 3-4 different sets with different options). Defensively, it has Will-O-Wisp, Pain Split for semi-reliable recovery (since it's fast enough to use it) and a fast Taunt. So to sum up everything, this thing beats pretty much all its checks majority of the time through the use of Taunt/Substitute/Nasty Plot/Will-O-Wisp (or you can use Destiny Bond and take something down you can't kill under the current circumstances), it has the second highest speed tier available, it can be used defensively... It can do many roles and sweep you off guard if you don't know what it's going to do to you. Also, this thing pretty much overshadows (get it?) pretty much all the other ghost types. With the only other ghost types being able to be used in LC being Gastly because of its secondary STAB and more powerful attacks. On the rest of the traits, it's outclassed.
Here we have that little friend who shits on your car right after you wash it... But that shouldn't be your reason to ban it, nor do I feel like there's any other reason to ban it. Why?
"1. Fletchling’s methods of getting around its checks are either extremely weak or incredibly easy to play around."
You use Natural Gift and run a bad berry and you have to depend on a prediction to pull that off and nail the switch-in. If you miss the prediction you lose the berry forever and can't handle the check with Fletchling, so you need your teammates to take care of the checks.
"2. Regardless of what coverage options Fletchling chooses to run, the sheer number of completely viable Pokemon that are still able to beat individual Fletchling sets is far more than that of any other LC suspect to date."
Rock types, Steel types and Electric Types pretty much take care of Fletchling, so that's a lot of checks, and having to be paired up with Diglett in order for most of them to be removed sort of gives away that it needs support to function. Also this thing doesn't restrict teambuilding as much as people want to make it seem since there's so many checks to it. The only pokemon I see being hurt from Fletchling being in the metagame is Snover, pretty much. Other birds have their niche such as the wall-breaker Doduo, Specs Taillow, Support Vullaby and Archen so it's not making them look like they're horrible compared to Fletchling.
2) Is Misdreavus / Fletchling making Little Cup not fun?
Little Cup is always fun. It's cutemons ffs.
3) Is a combination of 1 and 2 deterring individuals from playing Little Cup?
For the 4th time, I think the presence of "FUCK MISDREAVUS/FLETCHLING" has been present at some point. I don't think it's made anyone quit, though.
Clear decision: BAN MISDREAVUS and the new Subway motto: SUBWAY, KEEP FLETCH.
I'll be simple and honest, most of my points were covered by the rest of the users, so I'll quote a few of them and express myself, while trying not to make a new Twilight book.

Well, here we have the damsel in distress, although if you're facing this thing in battle, you're probably the one in distress. Misdreavus' is on a large number of teams, with good reason since it has all the good qualities of an offensive threat, and also has what it takes to be used defensively. It can fulfill the role of a cleric, spinblocker, setup sweeper, support and it has the ability to beat majority of its checks through the use of a few different moves or a different move-set overall (speaking of which, it uses about 3-4 different sets with different options). Defensively, it has Will-O-Wisp, Pain Split for semi-reliable recovery (since it's fast enough to use it) and a fast Taunt. So to sum up everything, this thing beats pretty much all its checks majority of the time through the use of Taunt/Substitute/Nasty Plot/Will-O-Wisp (or you can use Destiny Bond and take something down you can't kill under the current circumstances), it has the second highest speed tier available, it can be used defensively... It can do many roles and sweep you off guard if you don't know what it's going to do to you. Also, this thing pretty much overshadows (get it?) pretty much all the other ghost types. With the only other ghost types being able to be used in LC being Gastly because of its secondary STAB and more powerful attacks. On the rest of the traits, it's outclassed.

Here we have that little friend who shits on your car right after you wash it... But that shouldn't be your reason to ban it, nor do I feel like there's any other reason to ban it. Why?
"1. Fletchling’s methods of getting around its checks are either extremely weak or incredibly easy to play around."
You use Natural Gift and run a bad berry and you have to depend on a prediction to pull that off and nail the switch-in. If you miss the prediction you lose the berry forever and can't handle the check with Fletchling, so you need your teammates to take care of the checks.
"2. Regardless of what coverage options Fletchling chooses to run, the sheer number of completely viable Pokemon that are still able to beat individual Fletchling sets is far more than that of any other LC suspect to date."
Rock types, Steel types and Electric Types pretty much take care of Fletchling, so that's a lot of checks, and having to be paired up with Diglett in order for most of them to be removed sort of gives away that it needs support to function. Also this thing doesn't restrict teambuilding as much as people want to make it seem since there's so many checks to it. The only pokemon I see being hurt from Fletchling being in the metagame is Snover, pretty much. Other birds have their niche such as the wall-breaker Doduo, Specs Taillow, Support Vullaby and Archen so it's not making them look like they're horrible compared to Fletchling.
2) Is Misdreavus / Fletchling making Little Cup not fun?
Little Cup is always fun. It's cutemons ffs.
3) Is a combination of 1 and 2 deterring individuals from playing Little Cup?
For the 4th time, I think the presence of "FUCK MISDREAVUS/FLETCHLING" has been present at some point. I don't think it's made anyone quit, though.
Clear decision: BAN MISDREAVUS and the new Subway motto: SUBWAY, KEEP FLETCH.