My take: in general, questions of the form "Why does <governing body for sport> not implement <some feature>?" are very likely to be questions to which we can't get anything other than an opinion-based answer, as the governing body hasn't made any comment on the vast number of suggestions that are made to "improve" a sport; as such, the default position would be to close such questions.
Instant replay in football is a special case, as there has been extensive media coverage of the issue and (as corsiKa's answer shows) even comments on the matter from football's governing body. I appreciate this is a chicken-and-egg problem in that nobody's going to be able to add official comments on the matter if we close the question, but I think that's possibly better than leaving them open and getting a load of low-quality answers.
As an aside, I wouldn't particularly regard number of upvotes as an indicator of a good question - for a low traffic site like ours, that much more means "made it onto the network Hot Questions list" than anything else. Similarly, protection means "this question has had a number of bad answers" and says nothing about the quality of the question itself.