If the team is dead last in attendance and among the worst in television ratings, I wouldn't consider them fine. Their most recent world series win barely moved them up in the rankings and their 8 year old stadium is putting up End-of-Days Montreal Expo attendance numbers lately. Derek Jeter and his 4% stake in the Marlins has his work cut out for him.
The stadium was built specifically to go after a baseball team. Granted it's not the best design, but that's basically like saying the Magic play in a minor league hockey stadium because the Solar Bears use it.
It's literally in downtown St Pete. I don't know what the busy area of St. Pete is if that isn't it. It's barely over a mile from the waterfront.
That said, it would do better in Tampa. It is a crying shame the Ybor plan fell through. The fan base is there and the television ratings (while not the best, but still respectable) hint towards that.