Since the dawn of time, everyone involved complains about prices. No supplier has ever been satisfied with their share of retail prices. No retailer has even been satisfied with their markup. No consumer has even been happy with the price they paid. One proof the free market may be working properly: no one is happy with their share of the revenue stream, but, every competent participant survives, and flourishes.
So, does Apple violate any present legal statute? If not, then either get new legistlation into play, or let market forces do their bit. Suppliers have a choice: they do not have to write software, or create hardware, for the Apple market. If no one is forcing any developer to create for Apple products, why do they? Because Apple makes money. Insane amounts of money. And developers want in on that.
Consumers have choices as well: they can buy Apple products, or, purchase any of a number of functional, acceptable and often cheaper alternatives. Apple sells, in large part, due to perception. Thanks to decades of careful branding, the majority of consumers see Apple as the luxury option in computers and devices. As long as that holds, lots of people will pay (enthusiastically or reluctantly) the Apple premium, and live in the closed garden.