[glangdale]

That is a lifting regimen; it's just not your lifting regimen. While mine has generally been more like what you're talking about, there's nothing wrong with people doing that kind of interval training.

Curls and crunches often give normal people better aesthetics than they had before. Some people want a 4/5/6 bench/squat/dead, other people want to look slightly better at the beach without utterly killing themselves in the gym. I know a couple order of magnitude more people with good aesthetics who control their diet and do a relatively candy-ass workout vs those rare powerlifting dudes who never do any ab work yet have abs visible through their squat suits.