General :: More Games Not Support Profiles?

One of the games that I was addicted to, for quite a while, was Airport mania 2. One of the best features about this game is that it had support for multiple users. That way, on our family tablet, I could play it, my wife could play it, and so could my daughter, and all our progress and scores were separate. This was so awesome it's hard to describe. Kind of like having an epiphany.

So the main question is, why do other uber popular games like Angry Birds, Cut the Rope, etc not support multiple users.

Tablet are becoming more prevalent these days and most families I knew have one tablet that is shared. Not being able to separate my game scores and progress from those of other family members is really bad. I don't play most games any more because someone else in my family already does and I want to play a whole run by myself.

From a programming standpoint it doesn't seem like it'd be that hard. A separate set of stored data for each profile and a screen to let the user choose which set of data to load. However since very few games do this, I'm guessing there's more to it than that, or they just don't care..