The point is that Apple and MS both used the fact that vendors need them to make money (and while competitors for both exist, competitors yielded less likely return), and leveraged that position.
Microsoft got a lot of flak for just shipping IE with the OS, whereas Apple doesn't even allow alternate browser engines such as Firefox and Chrome on iOS.
Couple that with some capricious and silly rejecting or stonewalling of apps such as Google Voice and an Android magazine apps and I feel Apple is worse than Microsoft in asserting control over the ecosystem.
Oh, and Microsoft got flak because they were behaving in an anticompetitive way. Shipping your OS with only ine browser engine is usually no problem and only in very specific instances illegal.