I really stopped looking at r&b's denim over the last season or two because it typically was all the same, although I do kick myself over not buying a pair of grey jeans that were on sale at Barney's in December.
And my point was that I didn't like the streaky denim because it was too causal while the rest of my fit was more formal.
It's not hard to switch in jeans in certain situations with a sportcoat but it is still an oxymoron to call them "dressy" for the "socially unacceptable" example you stated. It also goes entirely against the invention and current-day use of jeans themselves as they were never intended for formal situations. I think I'd give in to your point the day that wifebeaters also achieve "dressy" status.