If you ask a user if they want to be prevented from installing an app, they'll most likely reply “no”, of course. If, however, they wake up and their phone is not behaving as usual due to borderline malware app they inadvertently installed, most people would be pissed. The age old freedom/responsibility tension.

To my surprise, many people had a similar questioning like you did in this thread, so it's probably not as obvious as I imagined.