obviously there wasn't a game constantly and always running, but it was absolutely the most played gamemode out of all of gmod tower, and you can't deny that I don't see how so many people would play it if the majority apparently don't like it.
and I can assume accelerate is going to be better on the new engine, and I want and expect it will be, but it's very clear with the games we have right now that's its on par with its source counterpart. Ballrace and virus are near unplayable with 200+ ping (which you will have most of the time) and that will only be worse with an extremely fast-paced racing game, which was one of the same problems source karts suffered from with gmod tower.
Also, uch will be so much better in the new engine, too, so the issues people have with uch may not be in crusaders.
It'll get much better once later releases come out, but UCH was a gamemode that worked very well in gmod and will be guaranteed to be played more than our current gamemodes (which have gotten very repetitive lately) and suffers from less the same issues as accelerate would. UCH is going to be even better on the new engine, so you would probably get more enjoyment out of it.
i personally would play either, of course, we all win in the end, but i would get a lot more playtime out of little crusaders as a whole, since the game is practically different each time, rather than accelerate. both will get made eventually, so it makes sense to start with the one people are guaranteed to play most, rather than end up with another planet panic