There's a four-blog round-robin post on this topic, summed up at Volokh. My two cents, based solely on personal experience, is that lawyers don't "hate" professors.
But I also have a sense that in the legal ethics field the relationship between profs and practitioner is unusually positive and tight. I'm going to speculate that that's because our field encourages the profs to be elbow-deep in actual lawyering. Thoughts, anyone? Perhaps another reason is the prevalence of adjuncts in the teaching of the topic, which fosters a cross-boundary appreciation.