Final Fantasy was the first RPG I ever played as well. I've been a big fan of all the 8bit and 16bit sequels up to VII on the PS1.
FFVIII was the first one that I quit after playing for only 6 or so hours. The repetitve summoning cutscenes and the grinding necessary to advance spells was a total bore fest. The story and environment were boring as well. I didn't care about any of the characters nor did I care for the futuristic feel (gun-swords?!... c'mon!). I tried to give it a shot but couldn't muster more than 6 hours.
I did enjoy IX thoroughly. The traditional art style worked for me as I felt the ultra-realistic look of VIII was a complete turn-off. But after that, my interest in the series was waaning like a bad relationship.
I tried Final Fantasy X and couldn't get past roughly six hours again. The focus on ultra-realistic graphics and drawn out summoning scenes just sucked the fun out of the fantasy for me. And I haven't even bothered with any sequel since.
I guess there is something to Nintendo's style of the "quiet protagonist" that holds a certain charm. When you over-develop a character you risk alienating the player and I feel the recent sequels suffer from this. I really think that is another reason besides the other points I mentioned above that caused me to feel disconnected to the games. I really didn't care and no changes to the core system could help that.
I reckon the Gamecube lost because of the complete lack of third party support that was carried over from the N64 days. The disc size issue, although contributuing, was a moot point by then.
SEGA was still in an uphill climb to regain customer support from its add-on debacle during the Genesis days. I used to be an avid supporter of Sega until I got burned by them releasing continous expensive add-ons and then discontinuing game development to concentrate on the next "hot" add-on.