The problem is that people usually pull out their secondary and kill you in one hit. So explosive focus doesn't always work.
It does if you pay attention and don't get ambushed.
So what, you want people too avoid every SMAW user or sneak up and backstab him every time? Then explosive focus wouldn't be worth it. If you go against a SMAW user, who knows who could be with him? Another SMAWer lurking around the bend.
Pseudo-official Co-'Pun'-isher of the Conduit 2 Board. Free-Lancer clan FTW! Too bad you can't join. http://cdn.memegenerator.net/instances/400x/23206541.jpg