I wonder if the differences are regional, or are mostly based upon your age and when you started playing pool. When I was in high school and college in the 80s and 90s, all we played was 8 ball and maybe a little cutthroat. Granted, it wasn't a serious pool-playing crowd, just regular high school and college kids.
After a long time away, I just got a table two years ago. I'm constantly hounding friends and neighbors to play. I find that the average guy who only plays here or there only knows 8 ball. A smaller subset has played some 9 ball. Absolutely no one that I play with (with the exception of if I meet someone here, or in a pool hall) has ever even heard of straight pool. None of them have ever played bank pool or one pocket either.
Enough rambling by me. Here's a question: in the 40s, 50s, 60s, were the casual, here and there players playing straight pool, or was it always a game for the more serious players?
Follow up question: do you think the rise of coin-operated bar tables, bar leagues, and the decline of pool halls contributed to a drop in popularity of straight pool?