This conspiracy thinking has been played again and again.
Few users cares for logging into some website from mobile Safari just to get a subpar experience over a native app (or a hybrid app), and that's not because Safari presents any kind of worse web experience than the desktop.
In fact Safari has often been the best mobile browser, but it still doesn't compete with the AppStore that much, as the most important things -- more than half a billion of credit cards on store, easy monetization, in-app purchases and full access to native APIs are missing from the web-app story.