Its true that in RoC creeping is more important than in TFT, BUT in TFT people creep as much as in RoC. That bull*%!# that "omg roc creep imba mass more than here" its totally false.
Towers is a part of the game in RoC, u have to make them or play agaisnt them, and they require SKILL.
Creeping is more effective in RoC because you don't take experience penalties, and you can creep past level 6. In tft, since it's less effective it actually becomes viable to interact with the other players early in the game.
Same thing with towers, since they're not as broken, you're allowed to use other tactics in tft without gimping yourself.