I think this is overkill, but indmar wants it done every year. For what it is worth, my dad has a 85 Mastercraft and has not greased the starter ever with no issues. I don't grease mine annually either and I haven't had starter issues.
If for some reason your starter ever got wet, or you happened to have your starter out for some reason, then maybe it's time to grease the starter bendix. Otherwise, I'd have to agree, major overkill.