Anyone know why people hate on Meghan Trainor?

My timeline + a decent amount of the Grammys thread were hating on her, and now there's a Tumblr post saying "well if meghan trainor can win a grammy I guess I can do anything" going lowkey viral with 11.5k notes

I can understand people hating on things like her type of music, her doo-wop style, etc. but she's cute, talented in several areas, has a sweet personality and Title is a solid album.

It just seems like a random person to pick on.