you guys realize that naga’s worst matchup is stall right? Naga is a LOT better at breaking offense in dia naga’s case and balance/bulky balance/fat teams without ditto with red orb. Stalls usually have a dedicated naga answer while carrying ditto in the back. I’m not saying naga can’t bop unprepared stall teams or that stall isn’t annoying, but this is a poor argument because are a) a lot better stallbreakers in the tier and b) if naga is banned stall will arguably benefit the least out of all playstyles
I'm also going to chime in here not to talk about Naga's MU against stall itself but what I believe may be the basis for where these opinions are being formed. From my own time spent on the suspect ladder and observing other players laddering for reqs, I saw extensive use of what i'll refer to as "Gimme that Click Stall" (referring to the showdown username who created and peaked the ladder with said team.) Gimme that Click (known as FOZ369 on smogon) posted it on the metagame forum after his peak and considering the sample teams are outdated, users in need of a team to ladder with seemed to flock to this build and as a result, it exploded in popularity on the suspect ladder.
Although it wasn't as common, Quantum Tesseract also laddered with a very solid stall build he created and passed it to a few users as well. These two teams combined with some other independent stall builds that I didn't see as often but were still definitely present are all testaments to how popular stall was on this ladder. So what i'm trying to say is consider the situation aspect alongside the matchup situation. Would this stall build be as present on the ladder if sample teams were easier to come by? Are you guys maybe coming to the conclusion that stall thrives in a Naga-less meta because the most experience you've had in mnm is on this stall-infested ladder? Have you tried Naga vs Gimme that Click stall or Quantum Tesseract's stall and do you really feel like it would make a dramatic impact vs these builds considering they were made during a era where Naga was present? I have used Naga numerous times against these specific builds and other stall and although it does a great job exerting pressure, it is SO far from an autowin and is forced to attempt to surgically pick apart ditto stalls without getting weakened itself.
To reinforce this point i'm going pull out the example of Gimme that Click's stall running sp def rest pdon with cleric support to prevent Naga from just running through his team. It also doesn't help that after very little chip, whether that be rocks or some other means, Naga cannot setup without the impending threat of ditto impostering its boosts and then flamethrowering Naga into oblivion. I'm not arguing that Red Orb Naga doesn't have a good MU against stall. That would be foolish; Naga is a fantastic mon that gives loads of builds and playstyles trouble and that's why it's here getting suspected. I'm simply providing examples of why it may not be quite as good of a MU as you guys seem to think and that good stall teams built during the Naga era know that it's a massive threat and have set stops in place to prevent an autoloss. I'm not going to speak on dia naga as much because that's an even easier stop for stall. Gimme that Click has ice beam blissey (which could also be exchanged for psychic if you wish to hit red orb naga as well,) ditto always revenges and if you're desperate you can even force weird situations with megaing vs not megaing with Audinite Kyurem (+2 sludge bomb is a little over a 50% roll to kill unmega'd Kyurem but you can still flirt with the possibility of them confidently clicking draco, getting burned by fairy typing and dying to earth power.
tl;dr Stall builds were spammed on this ladder possibly because they were some of the only readily available teams to take and use due to the outdated samples or maybe because people just wanted to use stall. Don't form opinions about Naga suppressing stall based off of only this and play/watch a few matches of stall vs naga to see if it makes as big of an impact as you think it does.