It is quite easy to say malware has to be banned and that a cool new game that hurts no-ones interest should be allowed. I guess anti-competitive policy can be understood and justified to a certain extent. But things are changing when the “own” product is obviously worse than the competition while market power is large enough to force the crowds to still buy the “own” product.
Nobody says Apple has bad “own” products. But it is maneuvering itself into a position where it has the power to defend bad “own” products and that certainly is a reason for concern.

The value of the question is you show an example where the distinction between right and wrong actually isn’t so clear. Adding functionality to web apps is a great idea. Probably some functions have a lot of benefits, and we might hope Apple will add them to mobile Safari by itself, while others are not such a good idea after all for security or privacy reasons. Can we really trust Apple to make the judgement? Can we trust Apple to take our interests sufficiently into account? And if we can today, can we still do so tomorrow?

Apple is usually very good at researching what their users want. They don’t like to add many extra features. Developers on the other hand are all about tricks and gadgets and little Easter egg extras. I’m sure you can see where a conflict may occur.