Oh, I'm okay with Shakir taking more reps from LD, and I think Crowder was certainly increasing and taking his snaps before the injury. I like McKenzie for the unique things he does, and despite having a bad game yesterday, he adds value to the team.
As for hating on him, it's the nature of the beast when someone has a bad showing. I remember people complaining about Gilmore when he gave up a TD one game. People who only focus on the negative will always find someone to pick on.