The more I think about it, the more I'm imagining there isn't much reason why Captains can't co-exist nicely with Skirmish in terms of faction balancing and combat mechanics once it's finished. Skirmish players never asked for crushthrough or sped up shock infantry. It's confirmed now that the developers added that mostly for SP and Captains. Skirmish players were against it, although a few people requested that shock infantry be given weak shields (while others disagreed). People need to get over insulting/downplaying the other mode just to make their own mode seem more important, since that's what's causing the troll comments.
I guess you can be annoyed at Skirmish getting new maps, but if anything, Skirmish players are more interested in fixes to combat than new maps (which would benefit all modes). If Captains is so reliant on new maps, it suggests it also needs improvements to the depth of its system, so it's not as reliant on new maps all the time before it gets tiresome. (People in Warband are happy to play on a small rotation of maps in Battle and never get tired of it, because the depth of strategy and combat is as timelessly appealing as Tetris, and teams are still coming up with new tactics for really old maps.) I'd have thought Captains players would want it to be the same for their mode, because how many times are maps going to be changed before eventually it's basically the same types of control points repeated?
After making changes to the combat, it's then simply a matter of improving the AI to use the changed mechanics effectively. I'm guessing that's what's being done with the archery mechanics. It's a bumpy road, but at least it is improving. If you want to hold back on this kind of progress just to retain the massively disappointing MP population established before the 1.5 patch, then you wouldn't be allowing it to be the best it can be.
It's also really ironic to hear Captains players blaming other modes for a dwindling playerbase when all the focus on Captains in the first place is responsible for the widely hated class system and non-existence of Battle mode, and hence the poor playerbase, despite all the hype and potential surrounding its launch. Although, I'm guessing SP and its affect on combat is what's really bringing down MP (but you can't deny it's far more popular, as opposed to the marginal difference between Captains and Skirmish).
You can say Captains is unique, maybe it is, but it's not the only unique/interesting mode. Captains is in Warband, and if you're suggesting BL's is different, Skirmish is most definitely completely new (calling it a cheap Mordhau is like calling Captains a cheap strategy game), and Siege is different with the multiple flags. Battle could have been different too if it included triple threat or something (as an option); that would have been really interesting.
What really needs to be split up is Captain and Skirmish from the other modes, so they don't have to put up with the class system. It could give a big boost to the scene whenever custom servers become a thing. Also, if Battle mode got included, and was split from Captain/Skirmish, I think a lot more people would be happy for Skirmish to take a backseat to Captains anyway.