To OP:
Yes, and No:
Yes, they are cumbersome to use and slow to react, and can find no meaningful use as
TRUE damage dealers.
No, because they are absolutely indispensable when facing underwater creatures, and, to a
lesser extent -- flyers.
=================
MY solution:
=================
Make them more reactive and responsive.
AND accurate.
Increase damage
slightly.
Problem solved, easy as that!
note: By "reactive" and "responsive" I mean that it should
take LESS TIME to draw / sheathe them,
AND to fire & reload them.
Basically, i
ncrease the animation speeds of EVERY ACTION THAT INVOLVES THE CROSSBOW !! 
It's annoying, really: Geralt is supposed to be a super-strong and super-quick mutant with insane reaction speeds,
yet his rate of fire and skill at usage of a Crossbow is actually
worse than that of common untrained highway bandits!
So...
Whaddya guys think?
.