the debated advantage is that you can show hands when doing so may influence opp's play at a later time. Say you are super-tight but play a huge bluff and show your cards, people may call your push with the nuts next time around if they aren't that observant. Etc. Sometimes it's good to push a tilting player completely over the edge as well.
As for the trouble of clicking muck, this is only a time issue as if you do not act then the default action is to muck the hand