Kyle tends to wear his emotions on his sleeve. He is who he is and will not change to appease the public. Given the cocky/confident attitude it rubs people the wrong way. It's not unlike Dale Earnhardt was, to a degree. A friend of mine summarizes it best, "Kyle Busch is more Dale Earnhardt than Dale Earnhardt Jr. is."
Personally I've seen him be a little ornery but I have no problem with it. He's one of the best drivers in NASCAR- all three series: Sprint Cup, Nationwide, Trucks. Busch won about 20 races in all three divisions each of the last two years.