I well remember the state of Windows during Win 98 and XP where most had no idea what they were downloading, and it seemed every machine had malware, hidden pop ups and 37 IE toolbars. I was constantly asked to clean up friend's machines from the damage done by Kazaa and its associated garbage or some other drive-by crap.
If a restrictive app store is the cost of avoiding that and gaining some minimum enforced standards, safety and confidence to avoid crapware, I've actually come to think it a price well worth paying.
The fact that Google are so laissez faire about the Android app store, and let so much crap in, just further highlights the potential benefits that Google aren't fully providing.