The muscles tag has bloated beyond all reason. Where it used to represent characters who were blatantly (often somewhat ridiculously) muscular, it has become used on every picture that has visible muscles. Simple visual musculature (and characters who just happened to be athletic) was originally the job of the toned tag, which has languished.
This can't even be blamed on the wiki entries. They're perfectly appropriate to the jobs the tags used to perform.
Since the problem wasn't caught sooner, fixing the muscles tag would be a huge project now. It clearly benefits from significant bad tagging momentum. What should be done?
Updated by MaShCr