Not surprised at all. What is surprising is the Apple tech world, who for years criticized the company for being obsessed with thinness and form over function, abandoning any of those critiques with the iPhone Air. There’s no selling point for the Air other than it’s super thin. But did anyone ask for a super thin phone?
Except by having the thin phones exist as part of an entirely separate product line, Apple can and should absolutely be given a break for making them. By having a single, flagship line of thin phones, back in the iPhone 6/6S/7/8 days they were
imposing those on their customers, whereas now they’re providing them with
choice. If there’s a market for those thin phones, I’m guessing Apple shareholders shouldn’t be complaining and users who don’t like it and now even have more choice than before, in the form of regular and pro models, even less so.
And to answer your question, yes, maybe some users really
did want a thin phone, and the Air isn’t really comparable to Apple’s older entries in that market, in that it’s way sturdier, it has much, much larger screen-to-body and battery-to-total-volume ratios, etc. But even considering those percursors, the iPhone SE 2 was a stupidly popular phone even in an era of somewhat thicker offerings. Sure, the customers who bought those were more price-conscious, but they survived for years and still do with thin phones just fine. As for the iPhone X and the iPhone Xs… they had their fans, for sure, and were the quirky flagships of the day. And the iPhone Air, as others have pointed out, is now filling their role.