>when Google spot it, they can unilaterally remove it.

Microsoft can achieve the same goal already through Windows Defender. My app was recently flagged as a trojan (false positive) and it would be wiped from users' computers before they could even run it.

>they also have the ability to remove it from devices where it was already installed.

That Microsoft can't do, but I'm not really sure that it's a good thing...

>The app store model probably also delivers security updates to legitimate apps more effectively than every developer managing their own distribution.

Citation needed there.