You can use roles to basically designate certain Pokemon, but you should never use roles to build a team.
Could you explain that a little more? I can certainly use roles to build a team and designate Pokémon at the same time. Weezing walls physical attacks, therefore Weezing is a physical wall. However, Donphan, Skarmory, Slowbro, etc. also wall physical attacks, thus they are physical walls too.
I can eleborate and say Weezing is a physical wall that counters Gyarados with Thunderbolt; Gliscor is a physical wall that counters Heracross with STAB Aerial Ace; Foretress is a physical wall that walls Staraptor and sets up Spikes/Stealth Rock/Toxic Spikes; etc. These are roles that these Pokémon can play. If Spiritomb walls Gallade then Spiritomb is a physical wall in the most general sense of the word. A Pokémon is a physical wall if and only if it can wall physical attacks; therefore it is a role. If a role is absent form a team, a team becomes weak in that respect.
Ex: My [example] team consists of Weavile, Foretress, Smeragle, SpecsMence, Blaziken, and Weezing whereas Weavile is a revenge killer, Foretress is a physical wall/spiker/spinner, Smeragle is a lead with Focus Sash, Spore, Mean Look and Baton Pass/Sleeper/Speed Passer, SpecsMence is a special sweeper, Blaziken is a physical sweeper, and Weezing is a secondary physical wall/Gyarados Counter/Hazer. My team lacks the role of a special wall such as Blissey, Cresselia, etc. With the lack of this general role, my team is weak, and therefore is not effective.
I have designated that Blissey is a special wall, that Snorlax is a special wall, that Regice is a special wall, that Tentacruel is a special wall, that Spiritomb is a special wall, etc, but I haven't used any of them in my team.
So by your logic, my team should not be built by roles: physical attacker, physical wall; special attacker; special wall; cleric; spinner; revenge killer; utility; etc. You haven't stated what it should be built out of. Infernape to sweep Foretress and Heatran with Flamethrower and Earthquake is still a role. Weezing to wall Gyarados and counter it with Thunderbolt or possibly Will-o-wisp is still a role, is it not?
In an earlier post, you said
"Add him on the team because he beats specific Pokemon your team cannot beat, and make absolutely sure to account for every single Pokemon." Surely you've read Jump's announcements that you cannot counter every single Pokémon. As I said above numerous times, it can be a role to counter a specific Pokémon your team otherwise have trouble with. Spritomb for Azelf, Weezing for Gyarados, etc, etc.
So unless you define your definition of a role, you're pretty much disproving yourself. Being super-specific is still a role, but a specific role, as mentioned above.
But don't get me wrong, I fully support you that we should be more specific in our roles, because being general leads to assumptions, and you know how to spell assume. [/cliché]
We should build our teams with
specific roles, not simply roles, and not simply concepts either, but
specific roles. Like the Weezing situation I like using.
Not flaming you or anything, because I fully 100% support your views. We need to start saying "Bulkydos Counter" instead of "physical wall" in our RMT threads. I'm merely reinforcing your views in a harsh way. =D
If this is a mockery of the teambuilding process, I apologize.
xD