There are restrictions that keep classes from rolling on gear they can't use at all (which was not always the case) and that's more or less the extent of how much we want to step in and control loot rolls.

There's just no clean solution to force people to only roll on specific items. An item may have a non-optimal stat on it where you may consider it good for a specific role, but it could still be a valid upgrade for someone. Those types of judgment calls are best left to the individuals in the group to talk out. We reserve that type of role labeling to class roles. If someone is acting in a way that the the other group members find objectionable, they're within their right to initiate a vote kick or leave the group themselves.

We're only willing to go to a certain point to control people, because at some point we're negatively affecting the majority just to control the behavior of a few. We have to draw the line somewhere. It sucks to have those experiences I agree, but ideally they're few, and there are options available to you to completely avoid or overcome them if you choose.