If people don't support Safari, it's because the free market has spoken and overwhelmingly chooses alternative options: https://gs.statcounter.com/browser-market-share/desktop/worl...
The story would be different, if Apple wasn't miserly with their native APIs and App distribution. But this is indeed a harmful and competition-restricting decision, even in Mozilla's opinion: https://mozilla.github.io/platform-tilt/
So I think we can safely assume that Apple's policy harms browser diversity by forcing their users to support a single minority option. If their users preferred a more feature-filled browser, we would never know; they aren't sincerely presented an alternative choice. If Apple wants their users to defend Safari, maybe they should invest in it until their browser (or Operating System, for that matter) competes with Chrome. Until then, they're promoting a megalomaniac solution and being a sore loser about it at the same time.