Not sure what game those people were watching to be honest (Although I didn't actually hear the comments). I live in the US and we have something over here called NBC Sports Live Extra, which allows you to "Legally" watch every single premier league game on the web, even if it's not on a TV channel. I've streamed every game this year (Apart from the game against Man City, that I was actually able to attend) and I'll be honest, at first I thought he was a right plonker.
For me Ayew turned it around after he came on against Birmingham in the league cup game. He's shown he can run with ball, has a decent shot from distance and has the ability to finish. Yeah I know he missed that sitter today, but if anyone saw the chances Sterling and De Bruyne missed against us in the Man City game, that can happen to anyone.
The kid definitely put a shift in today and always seemed to want the ball. If giving it 100% and getting on the score sheet isn't enough, I'm not sure what else the guy could do?