I don't care for a truly excessive grind -- I play RPGs, so I'm accustomed to some grinding -- or certain kinds of locked content, like Forza's unicorns for example...but I cannot think of any game that I personally felt was made better by having everything unlocked and accessible at the start.
A game with everything available straight away tends to hold my interest about as long as a game I've already beaten, because that's what it feels like.