The difference is between shitty products crowding out competition and great products crowding out competition. Therein lies the axis of opinion I think.
"Great" products preventing even better products from coming to market is no better than shitty products preventing better products from coming to market. And the reason for that is that the goalposts for "great" are very easy to move. Once people see that something is better, they quickly demote the old "great".
And that said, Safari on iOS may well be a case of shitty products crowding out competition. Can you get a browser with the stock iOS WebKit but the V8 JS engine on there instead of JavaScriptCore? Nope. Can you get a browser supporting web features that the stock WebKit on iOS doesn't happen to support? Nope. Lots of other things that could be done much better than Mobile Safari.... and yet they can't be, because such apps could not be offered through the Apple app store.
