she explained how her and her farmville friends have been protesting facebook. she was happy because once they "got facebook to change something by a certain deadline." (not sure what facebook change this was, but obviously it was a coincidence.) then she explained why -- "it's so annoying when you go to facebook and it's all of these things about people being friends with friends. who cares? i have to click something like 'see related stories' to see all my farmville notifications. it's a total mess with all that stuff about friends in there."
basically, my mom doesn't think anything of facebook's core product. it gets in her way. ("some of the people in our farmville/mafia wars groups have left facebook because of how annoying it is!") she doesn't know that friends are supposed to be people that you know, or that it's a site about keeping up to date with people. she just knows that it's a place to play farmville and mafia wars, and the rest is the fluff.
Now, if iPad users monetize better or they can be more spammy than Facebook users, then we might be talking. But you still have to deal with keeping two separate codebases in sync while releasing new features nearly every day.
I haven't heard stories about parents joining FB because of games here in Finland, that's why I'm curious to learn more.