WoW (and Rift - and yes I played both; end-game and pvp) simply have more "buttons" available to press, and (as someone also touched on above) I would hardly look at all these "buttons" as opportunities for a player to make smart decisions while playing. They aren't "smart decisions" - they were how you played your class: it's called spell/ability rotation. And if you didn't do it properly you weren't able to play your class/role properly (i.e., tank not holding enough threat, DPS not, well, DPSing enough, etc. etc.). So the only decision was to either a) play bad, or b) play as the class was programmed. Even though PVP was more dynamic than PVE (in the sense that NPCs are far more predictable/learnable than PCs are) there was even still a notion of proper spell/ability rotation when playing vs. class A, or vs. Class B, etc. etc. So yeah, more "buttons" <> "the opportunity to make smart decisions with skills" (or, for you non Access/SQL readers, "<>" = "=/=" ... which is a perversion in any language IMO~~)

It's understandable that some people feel they have no choice in whether or not to perform a combo, or that they feel it's the only choice - but that's simply not true. The Ifrit fight itself is a prime example on making smart decisions or not:
  • Do I wait to use a WS/ability, or do I risk getting caught in the animation and get blown up by a plume/eruption that I could have anticipated but simply ignored because I have ADHD or something like that and need insta-gratification by smashing 10 buttons per second?
  • Do I stretch out the combo as long as possible (e.g., wait until the Combo-buff - w/e it's called - nearly times out), or do I LOL-I-DON'T-LIKE-TO-PAY-ATTENTION-TO-WHAT'S-GOING-ON-BECAUSE-THE-PRETTY-PINK-LIGHT-ON-MY-ACTION-BAR-IS-TOO-PRETTY-NOT-TO-PRESS~ and try and perform the full combo w/o regards to, well, what the he!! is going on?
  • Do I even try to start a combo, or should I just use the first 10sec c/d WS and at least provide somewhat decent DoT while I wait for the right opportunity to do some burst DD with a combo?
  • Etc. etc.

Failing to make the right (or, "smart") decision in this fight will either leave you a) dead, or b) nearly dead; and you can't a) do DD or perform your role when you're dead (unless I have a different client installed on my PC or something), or b) are taking unnecessary/unplanned attention away from your healer(s) form the tank which risks the entire fight to begin with. And this is just with the Ifrit fight - Moogle, Strongholds, etc., have different dynamics to them and require different "smart decisions" to be made.