Thickness of Apple Watch is right on par with many mechanical watches that are quite popular amongst watch-wearing individuals.
If you see a band poorly fit, that's all there is too it. Someone chose the wrong case size, band size, or didn't put it on right. This is really common, getting the wrong fit. I mean, just about every single picture I've seen showing the milanese band, for example, has the band on backwards/upside down.
There is absolutely nothing bad or strange about how the Apple Watch fits compared to real watches. It's fine. Get one that actually fits and a band that works well with your arm. It's not the watch itself that is a problem when you see an odd fit.