Back east...it's a little true...especially for the oldtimers...back in the old days you saw marina and yard separately a bit more.
But were's not fussy enough to pass laws over it...and some "marinas" by name provide more and better services than some "boat yards"...
So I'm guessing where the vast majority of boaters in the US are really don't care much what you call them.
I think there's a thread someplace where people are getting huffy over the words "salon" and "saloon"...maybe the marina/yard controversy belongs there with other highly important boating issues.