Hmm I think this thread is deviating a little too much from the topic. Rather than focusing on whether FT should be disliked, the thread is asking whether Mashima is aware.
I'm not hooked into twitter or other media that'd help me answer that. There was a volume afterword(?) where he was talking about the 'recent made-ups' in the Alvarez Arc. The way he worded it by adding in some expression, like a sweat-drop or similar, made me think he's aware of some of the backlash regarding plotholes/contrivances used in his work.
On top of that, in my opinion artists' like Hiro who are wired into twitter and the like, would know their fans. I worry about famous people sometimes who get hated on, so I hope he's alright. Well, it's part of the parcel I suppose.
So to answer the thread title, I'd say yes.