> can a company make the world better by making proprietary software?

If you assume a company that does not have any profit driven incentive to be anti-competitive and less accessible to some people, yes. But that's like assuming dictatorship can work if the dictator is just wise and benevolent enough. It's nice to think about but not viable in reality.

> it raises the barrier to entry and forces companies to choose agressive and hostile business models in order to get that investment back

You assume that corporations would not choose aggressive and hostile business models if they weren't forced to, which is obviously wrong.

> If a new "More Ethical Apple" could be started instantly with no software investment

This would not be possible with licenses that allow Apple to keep everything proprietary, which is what any profit driven company is incentivized to do. In other words, you need GPL for this scenario to be even theoretically possible.