I think jjroland hit it right on the head. If you don't want to see nudity you have the option not to see it.
I would just like a clear HONEST reason for the thumbnail issue. I can deal with whatever (inane) reason they come up with, however I would just like the true motivating reason for it.
At the end of the day sadly, you can either put up with it or post on other sites.  And as we have seen, there are artists whose style is on the racier side are leaving to do exactly that.