Why not enforce the follow-on?

It was a thrilling but frustrating end to the match in Antigua. I find it difficult to understand why captains often don’t enforce the follow-on. The beauty of the follow-on is that it gives the side enforcing it two chances to win, either by bowling out the batting side cheaply enough to win by an innings or by leaving a modest target to get in the fourth innings. The reason in this match was supposed to have to do with the England bowlers being tired, but surely pressing home the advantage of bowling out West Indies cheaply would have left England in more control. England would have been pressing for runs in the fourth innings instead of trying to winkle out the West Indies tail.