Fielding % is not a valuable stat on its own, but it's not totally useless. The Red Sox have the most errors in MLB, the worst fielding percentage, and by far the most unearned runs allowed.
A lot of fielding misplays do occur on balls hit right at the fielder or on bad throws, right? Those have nothing to do with range.
Of course the fact that fielding % doesn't take any range factors into account means that other numbers have to be looked at as well.