Their rugby careers are definitely not over. They'll get picked up by a French or English team and they'll both carry on. Their stock has both dropped quite a bit and I doubt either will play in Ulster/Ireland again but they will continue to play professional rugby.
This whole situation has been such a mess. From their own behaviour, to people including Irish politicians effectively questioning the verdict of the trial, to the complete lack of measure in any of the commentary around the situation. I fucking despise trial-by-social-media. Personally, while I think some of the messages were fairly abhorrent, my opinion would have been that they were found not guilty and should have been allowed to carry on with their careers in Ireland. But the writing was on the wall there from a long way back. I think the IRFU are sending a message to all their other players as much as anything - put yourself in this position and there will be severe consequences.
And on your last sentence, we can't prove it obviously but you're absolutely right. Professional rugby players tend to be young, have high profiles and plenty of money. You know well that they aren't the only ones.
I also think there have been some really excellent discussions on consent, which oddly have been lead by
sports journalists such as these guys. There's a chance to educate people here but you need to go searching for it in the middle of all the noise.