I don't know. It was just a hypothesis, it seems to be common enough that artists drop out of games, that it wouldn't strike me as an unusual excuse. Again, and I don't know for sure, but it feels to me like there are very few graphic artists that work exclusively on explicit content. I would imagine that most of those you see on twitter are like accountants or whatever in their day jobs and they're just drawing porn as a hobby. If you're a graphic artists as career you have to have a portfolio and showing your ahego face Lena to the HR department of Google likely isn't winning you the job.