There are certainly bad comments about her when i tell people i support KARA. However, after watching the variety shows she's on, I realized the image she portrays were meant as a joke and just for entertainment.
For me, whenever i win a game i would just exclaim "can someone PLEASEEEE tell me why im such a pro???". My friends just enjoyed laughing at my sarcasm. I guess acting cocky to make others laugh only works among close friends and for people who "understands" the humor.
In Gyuri's case, I guess there just aren't many people who "understand" her humor.