I really can't agree with this at all. I have been in plenty of games that explicitly allow monster races and evil characters but aren't evil campaigns, in which case that is just you as the player making a really dumb decision.
I have also been in many Evil campaigns and I don't think a single one of them didn't have at least a few evil creatures we had to fight, sure there was a larger number of good enemies but evil enemies were still there too.
There are enough issues with having a character that only has two things that it can do, has to invest ~50% of your build to doing said things, and those things don't scale that I can't reasonably see this thing getting over +0. Also as has been pointed out with only a fly speed of 20 you will need to be investing to bump up the speed otherwise enemies can just stay out of range and attack from afar.