Early N scale had a lot in common with O-27, and much of the modern stuff still does. That isn't necessarily bad. Sure, O-27 has sharp curves, truck mounted couplers, cars sit too high, giant rail and bad tie spacing, etc, but it runs, it sells, and people have built operating layouts with it.
N and O seem to share the tinplate/scale combination. which HO and S have gotten away from. It makes for some confusion in trains and track, but also means a larger market for related items. Scenery, structures, vehicles, etc are the same for both groups.