It's pretty simple really. Sports fans don't like to see their team lose. Especially to the same team for the better part of a decade. That's the main thing. The timing of the chase and fans' opinions on it coupled with a sudden streak of championships by one person when their driver "would have won the champion" this year or that year under the old system will cause fans to come up any reason to discredit the dominance of that team, therefore making their drivers' loss not seem so bad. You also need to remember the fact that the 48 team has been caught "cheating" over 10 times in that time frame. So you've got a bunch of angry race fans looking for anything they can to discredit the 48 right after a huge change in the points system that they all hate and then they get caught cheating so many times... it's ammunition for these angry fans. "He only did this because of the chase.. Jeff Gordon would have won this year and Carl Edwards would have won this year and bla bla bla bla bla. He's a cheater anyway, probably has a trick engine".... Oh and let's not forget that he works for the same motorsports power house that brought in wonder boy about 10 years earlier to dethrone Dale Earnhardt. The same team that is accused of having NASCAR in their pocket.
So you've got the people that are Dale Earnhardt fans that may not like Hendrick because of Jeff Gordon and Hendricks continued dominance with Jimmie Johnson.
Then you've got the Jeff Gordon fans that don't like him for the same reasons.
You've got the people that hate the chase and think it's a scam and he doesn't deserve the championships.
Then there's the "He's a dirty rotten cheater!" crowd.
Then there's the "Hendrick has NASCAR in their pocket" people.
Oh! ...and don't forget Carl Edwards, Jeff Gordon, Mark Martin, Denny Hamlin and Matt Kenseth fans
...and I just don't like him because he's boring. I can also admit that I just don't like him because he just wins too many damn races.... like I said no one likes seeing their driver lose... especially to the same guy over and over.