The main idea for a crossbow was that it really was a low trained weapon, that you could give it to a no-skill peasant battalion and with a little time have a group that was a decent shot.
Keep in mind that this was compared to proper archers who needed a lifetime of training.
A good archer would completely outclass a crossbowman, but it would take longer for the archer to get to that point.
What I propose it that we have crossbows, BUT we give them limitations, namely
1. That they are more of a starter weapon.
2. That they can only give you a limited amount of experience (maybe stop giving experience after your archery is 30 or so)
So for someone who has never used a bow (archery 5 or so) they are an easier concept, they can do more damage, but you stop getting any better with them at around level 25, after that bows start to become better at damage.
This means that people who only want an option for ranged weapons, but don't have much commitment can still have a weapon that they are decent at, while someone who wants the full ranged experience doesn't have to touch them.
How does that sound?