but it's still a staple of PC RPGs to feature more complicated systems
Not really. While this could possibly be the case with MMOs and more modern RPGs -- I wouldn't know because I'm too cheap for the former and don't have a video card generally capable of playing the latter -- most PC RPGs don't have complicated systems.
True, there were games like Realms of Arkania and MegaTravller that had endless goddamn skills (most of which didn't actually do anything) and confusing, ornate battle systems, but those aren't the norm.
The big difference with PC RPGs is that a lot of turn-based ones favor gridded combat where you can move around. This doesn't tend to be horrible complex. Think Arc the Lad or something. As for the rest... they're generally about on part with SMT games as far as complexity goes. I mean, yes, Xeen has skills and some nominal notion of ranged combat and needing to eat or whatever, but none of these were complicated things to do.
I guess what I'm trying to say is that JRPGs have systems. PC RPGs don't really have systems in the same sense. PC RPGs have rules, which are generally numerous but fairly simple. Mini-gameish things like VS's combo chaining or FFX's sphere grid or whatever wouldn't fly in a PC RPG.