What makes certain QTE's enjoyable and what makes them fall flat?

[F0X]

The Mario RPGs you listed do not use QTEs (well, at least not in the way I'm used to thinking about them). There is no "Press X to Not Die" in those games - they simply give the option to perform well-timed button presses (often in a short window and without a button prompt), which requires a level of skill that can be improved over time. That's legitimate gameplay, with similarities to rhythm games.

For your general question, I don't like the use of QTEs in combat. If I want to do a flashy finishing move, I want to perform it, not watch it happen without any control over the action. I'm not fond of the idea of cutscenes during which I occasionally press buttons in order to continue the cutscene. At that point, why not just have a cool cutscene instead of boring me with some of the most simplistic gameplay imaginable?

QTEs are best implemented when there are multiple options, particularly not related to combat. That's why I liked Heavy Rain and The Walking Dead - games that really deliver on providing an interactive story, where I'm forced to make hard decisions. It's great, because then I become responsible for the direction of the plot, which invests me deeper. However, just having a dialogue tree is usually enough for those types of games, so it's nothing revolutionary. Things certainly fall apart when QTE-heavy combat is shoehorned in. I hate that so much.