Depends on the Pokemon and the trainer, really. You can hand someone a team of six Ubers, but if they don't know how to use them efficiently, they won't win battles at all against skilled trainers. Similarly, not all Pokemon are created equal. Delibird is not going to be good, like, ever.
Please don't self-censor. It just looks dumb. If you are uncomfortable with using that language, then just don't use it.
Several do learn it, but a spinner often negates other things it can do. And it means you give up a slot. AND it also means it can easily be blocked by Ghost types. In fact, Claydol is pretty easily countered by Rotom forms and Sub-Pain Split Gengar.