Seems pretty clear to me: OK to rip a cycling personality. OK to rip a post. Not OK to rip a poster. It's pretty standard. And it's one of the reasons the old SNL skit was so funny when Akroyd would say "Jane, you ignorant s!ut!" He was violating all rules of civil debate.
Lance is an idiot! (fair game)
Your post was idiotic! (fair game)
You are an idiot! (out of bounds)
Lance is an idiot! (fair game)
Your post was idiotic! (fair game)
You are an idiot! (out of bounds)