No, it's not a viable strategy at all, but scrubs do it anyway. It makes learning a new character who doesn't have great chipping options very difficult.
[youtube:tejpatf1]4FBNtkJuj4g[/youtube:tejpatf1]
^Check out this match, for example. The player on the left (Cyclops, Strider, Akuma team) does almost NOTHING but sitting around blocking the entire match. Thus, the other guy chose an Iceman/Doom combo just to slowly chip him to death. It takes FOREVER, and most of all, it isn't fun.
And yes, I have played this guy. He sent me angry messages after my Cable/Sentinel/Cyclops team slowly but surely chipped his team to death. :lol: