Minato used FTG so much because it was just so damn useful:
-No matter how fast the opponent is, he can avoid them since FTG is instantaneous.
-There's no apparent limitations on the technique distance-wise, and can even transfer massive entities like Kurama.
-Appears to use very little chakra to jump between marked objects
-The "Technique Formula" markers can be applied to basically anything.
The question isn't to ask why Minato used FTG so much, but why would anyone expect him not to? :shrug: He's never been shown to be pressured by an opponent, and FTG pretty much makes sure that won't happen. He obviously had other skills, but with a technique like that with no apparent drawbacks other than being restricted to marked objects and no apparent counter, I think it's something that any ninja would use a great deal.
It's quite stupid to say he became Hokage SOLELY because of FTG.