I think that is a factor, especially with Conditt starting to play so well. He's better than Foster right now and he'll be even better by the start of the season next year so Foster not as likely to start vs playing at Iowa.
All of the arguments re: which team puts more players in the NBA, etc. don't really matter that much when you look at the recent research on decision making including brain imaging studies. People make decisions based primarily on emotional reasons and then select the facts that support their rationalization of that decision. Foster has had an emotional connection wased onith Iowa since he was a kid so difficult to overcome that. How many Iowa football players are playing for ISU because they grew up ISU fans? For that matter, would Conditt have come to Ames if he didn't have an emotional connection because his Dad played here?