It's not that hard to deal with bow spammers tbh and banning them makes absolutely no sense. You've just got to learn all the different ways to deal with them.
1) I find that few bow spammers can shoot well straight up, so... get in line with them (if not in line... get in line), build up (double ladder tower is useful for speed), godbridge over them, if they hit while you are bridging then if you're in line then they just knock you back a bit onto your own bridge and you can just continue to sprint forward and the god bridge carries on without having to restart it (mostly). I find few bow spammers move so that they're not in line with you and if they do well just move until you're back in line with them). Once you've bridged so that they're shooting up at a certain angle I find they're not great usually at shooting up. So either continue over them or drop and get them or for fun drop a stack of TNT on them.
2) If they're dumb enough to be walking across unsafe bridges, grab a bow and knock them off.
3) Tunnel bridge.. slow but works.
4) TNT canon them from an obs bridge (if you can get close enough). Just for fun as it can annoy them back.
5) Get in line with them (important), gotbridge a bit, throw up a wall builder on the end for some cover, throw up a ladder tower, godbridge a bit, repeat, easy enough to get over most of them.
There are plenty of other techniques that I can't think of right now.