I've never had an issue with people licking plates, neither has my dog. I find it hard to see why anybody would - after all, 'waste not want not'? The majority of people, however, seem to set out on a vendetta to all of us innocent plate licking beings.
Society has moved on from what it used to be, blacks are now acceptable and gays are gaining rights; so with our ever increasingly liberal viewpoint I fail to see why plate-licking is unacceptable.
I hate to single out a particular group, but mothers are our most common predator. Plate licking to them is as filthy an act as masturbation. It's like taking your school books, ejaculating all over them and chucking them into a fire.
You just don't do it.
I fully support anybody that openly licks plates, and I congratulate everybody that gets dirty looks for doing it.