Except that meddling thing called the market.
"The market" doesn't exist on the iOS system, nor does the "the market" work without referees.
Until the app market, on every single platform, is as open as the pc/mac, I consider it unacceptable. I don't trust Apple nor do I trust Google to do the right things. I should be able to install whatever I want, without any involvement from either company in any fashion.
It's my hardware.