Drizzle wasn't banned because it isn't broken alone, Swift Swim wasn't banned because it isn't broken alone, Politoed wasn't banned because it isn't broken alone. Drizzle + Swift Swim as a combination was the very thing that was broken, so it got banned, while other obviously non-broken strategies could still be used, such as Rain stall and Thunder/Hurricane/Hydro Pump, the difference being not every relevant user of those strategies were broken while almost everything that got Swift Swim could abuse perma rain to the point of broken.
Same thing I see here with Baton Pass. I'm pretty sure this argument has already been said but: Baton Pass is not broken on its own, Speed Boost + Baton Pass is not broken on its own, Magic Bounce + Baton Pass is not broken on its own, Magic Bounce + Speed Boost + Baton Pass is not broken, etc. It's a combination of 6 Pokemon that make it broken. Banning any individual move or Pokemon would make no sense in this case when they are obviously not at fault.
If you were a newcomer to Smogon and saw the banlist, what would you think of a ban on, say, the combination of Magic Bounce + Speed Boost? I get that this is hardly a good argument but the point is that banning a combo of Magic Bounce + Speed Boost or something similar is unnecessarily complicated. How would you explain this complex ban? "oh this combo is banned because Espeon and Scolipede with Baton Pass are commonly seen on Baton Pass chains and BP chains are broken"? I do see the reasoning behind these proposals but I believe they are unnecessarily complex and difficult to understand at surface value; they don't get to the core of what is broken. Every single proposal so far, be it for a Speed Boost + Magic Bounce ban, boils down to how they are broken because of Baton Pass.
If that was difficult to understand, see it this way: if you take away Baton Pass, would Scolipede or Espeon be broken? Nah. If you take away Scolipede and Espeon, would BP chains be broken? They'll surely be less powerful but it's still very easy to play around a team without phazers or Taunt users. Why are we probing so far when Baton Pass is obviously the issue?
Now, I've stated that BP alone is not broken, and I'm sure many of us would agree. It's the combination of BP users in a team that make it so. Hence, I'm all for the argument of ban multiple BP users per team. Simple, to the point. No need for roundabout bans of Espeon/Scolipede/whatever because themselves alone aren't the issue. Of course, there comes the issue of what number is the limit. But going by the number of important Pokemon in BP teams, we should be able to derive a number. For instance, every full BP chain needs a speed booster, a magic bounce/soundproof user, and a defense booster at the bare minimum. I propose that limiting 3 baton pass users is a good number that would significantly nerf BP chains while retaining the benefit of every section of BP chains on their own.