When did it become socially acceptable to wear pajamas in public?

I am a product of the 80's so I get Madonna's revolution regarding underware as outerware but really. I was at Kroger this weekend and saw someone wearing their house slippers (fuzzy and pink), pajama pants and a t-shirt. This isn't the first time but a common occurance these days. I even met a buyer at a house this weekend and they were in PJ's (it was 1pm and it was a $200k house). I wonder what the seller would have thought had they seen them. This buyer is qualified for over $300k and ready to purchase so they are serious but the question is will they be taken seriously. Am I old fashioned? I am in my late 30's now and I guess that I am just out of touch with the trends but you will not catch me in public in my PJ's, I won't even run to the mailbox or chase the dog......it'll have to wait till I'm dressed.