It's hard for me to say how representative my non-techie friends are, but nearly all have some understanding that the App Store is tightly controlled by Apple, and not always in ways they agree with (apps being banned or not approved makes mainstream news semi-regularly). They accept it because they still like the iPhone more than the alternatives, but I wouldn't say that they are 100% happy with the way the App Store is run. Some join random "tell apple to unban [thing]" groups on Facebook periodically.