I don't think it was always this way though. I remember the older guys in So Cal were well-dressed until about the end of the 80s. The wave of preppy kept a bunch of people looking pretty sharp. Then it all seemed to go downhill. Around the same time, many of the "classic" mens shops closed up. Maybe it was the influence of designer or branded clothes or just cheaper production or the rise of discounters. Whatever happened, I agree Americans got used to thinking about clothes as disposable cheap stuff you only buy on sale.
Did you ever shop at At Ease in Fashion Island? I remember getting my polos and topsiders there in the 80's.