Both SC and Tekken have their ways of dissuading button mashers but the fact of the matter is that there will always be at least one character that is really really button mashing friendly. In SC2/3 it's Maxi and in T5 it's Steve. Any half decent player will easily overcome a button masher through good Punisher play.

Beating a button masher in SC2/3 has alwasy been easy for me since my best character also happens to be the best punisher in the game. Cassandra baits the CH and rushes in with a 236B(:B for SC3). Follow up with Cassandra's strong okizeme (wake up game) and you can win a round in just a matter of seconds.

In Tekken, baiting for CH is just a way of life so not being to stop a button masher is indicative of your own ignorance of how this game is supposed to be played. Paul has an awesome SS and SW so landing a CH qcf+2 will cause button mashers to cry. Send them into a wall so you can follow with another just to make it worse. Kazuya players tend to space out really well, looking for that elusive CH EWGF (Electric Wind God Fist). Xiaoyu can HYP and RDS (moves her left and right) away from anything. Finally, Steve is so awesome/broken he doesn't even need to block to beat button mashers. 4, 2. Repeat. Steve wins. Actually scratch that: 1, 2, 1 will interrupt ANYTHING an opponent throws at him anyway.