depending on the reasons why for the red (ie a "professional foul" vs hacking down the opponent violently) its a 1 game ban not 3. I don't like the rule but I'd wonder how many more incidents like Suarez in the world cup you'd get if it was just a pen, I'm cynical enough to believe some players would take their chances and blatantly try to stop the goal and take their chances with a pen.
Ahhh yes, forgot about that. Until it happened to Yanga-Mbiwa I'd genuinely never heard of the rule.