Horrors! How, Jimmy? How? Shatner is so universally liked! Who can dislike the Shat? Everyone loves the Shat. Gotta love the Shat.
Obviously, the "hate thing" has taken on a life of its own. I think it's predicated on the popular notion that everyone onscreen in the TV biz must get along well off camera. Doesn't have to be so. Two classic examples:
-- Some of the cast of M*A*S*H
had issues with Gary Burghoff in the early years. He was apparently a quite difficult person to get along with, but things got much better in his later seasons. This is well documented.
-- Andy Griffith and Frances Bavier (sweet old Aunt Bee) didn't get along at all. They barely even talked to each other off camera. She was also apparently some kind of diva, and not too well liked by anyone on the set. Griffith and Bavier didn't reconcile their differences until she was basically on her deathbed many years after the show ended. And that's well documented, too.
So, Doohan apparently didn't care for Shatner? Not to be facetious, but why does it matter? Why is it novel?