Why does Johnathan Grenard hate us now?

All i've seen is videos is him talking s**t about us, his former teamates and the organization? He did it on the field during mic'd up and on the post game interview?? Is that just a thing to s**t on your former team once you leave??? I seriously always liked the dude until now, I literally thought it was just the competitiveness of the game but, he seems to genuinely hate the Texans.