I agree they're being dicks(even though we have famously never received a straight-story from Rogue Amoeba), but this is not anti-trust/anti-competitive or monopolistic.
To get into the hot water that Microsoft did, you need to have a monopoly on an open market, which requires that there is no reasonable choice in the market. Android proves every day that there is indeed choice - and it's actually cheaper and easier to get involved with Android. Android is 56% of the market in comparison to iOS's 23% market share. iOS is only a revenue leader, which is like saying DM Chrysler has a monopoly on rich people.
Secondly the monopolistic abuses need to influence situations that would normally be out of their control. Anyone can choose to stop selling Brand X in their own store for example, it doesn't matter how popular the store is/or how much revenue they earn.
Once those are satisfied they need to do things which leverage their position to trample competition. E.g. Microsoft deliberately changed the function of their APIs to make quicktime unstable. Microsoft deliberately fragmented Java with their own flavour to stifle Sun and the cross platform movement, Microsoft deliberately enforced a web browser on their users as a way to prevent Netscape innovating the web-app scene. Microsoft deliberately forced vendors to sell Windows-only systems by threatening them with severe price hikes if they packaged OS/2.
That is anticompetitive, and they were excellent at it. Apple always wanted a curated store and have deliberately structured their store for this reason.
My comparison to Microsoft may be a bad analogy: while they did act anti-competitively, it's different than what Apple is doing now. As bad as Windows lock-in was, they never set themselves up as the only store in town, and they were seldom hostile to developers building a business on their platform (if anything, it was the opposite).
I know Apple doesn't hold even the majority of the market, and they won't be king forever, as the MS story demonstrates. What concerns me is that they're defining the new norm (the Windows 8 store follows heavily in their footsteps). If the next OS vendor to take the crown successfully practices the same "our way or the highway" approach, it will be bad for the marketplace, consumers, and society.
Maybe it's a self-correcting problem. But make no mistake: it is a problem.
I generally follow and agree with the gist of your point, it's bad business to shut down people who have invested money into your ecosystem or something that helps sell your product. Fortunately market forces correct this, which is why there has been a trend for developers (especially smaller ones) to switch to Android, or boycott iOS outright. (E.g. If you have budget for one implementation of a title that may be risk rejection by Apple, then you'd naturally choose to develop for Android first, or exclusively.)
However the comparison statements given are off the mark, such as this one regarding Microsoft:
>they were seldom hostile to developers building a business on their platform (if anything, it was the opposite).
Noting my examples from the above comment - Microsoft were entirely hostile to software titles which could compete or create competition for Microsoft's products, or fields they were interested in owning. This isn't a matter of speculation, it was tested in court and proven as fact. Microsoft's deliberate interference were found to have damaged (in many cases permanently) the competitors that they targeted. Of all the 'evil' stuff that Apple/Google/Oracle/etc have done, it does not even compare with what Microsoft did, heck the halloween document alone is trove of a corporation acting evil.
To get into the hot water that Microsoft did, you need to have a monopoly on an open market, which requires that there is no reasonable choice in the market. Android proves every day that there is indeed choice - and it's actually cheaper and easier to get involved with Android. Android is 56% of the market in comparison to iOS's 23% market share. iOS is only a revenue leader, which is like saying DM Chrysler has a monopoly on rich people.
Secondly the monopolistic abuses need to influence situations that would normally be out of their control. Anyone can choose to stop selling Brand X in their own store for example, it doesn't matter how popular the store is/or how much revenue they earn.
Once those are satisfied they need to do things which leverage their position to trample competition. E.g. Microsoft deliberately changed the function of their APIs to make quicktime unstable. Microsoft deliberately fragmented Java with their own flavour to stifle Sun and the cross platform movement, Microsoft deliberately enforced a web browser on their users as a way to prevent Netscape innovating the web-app scene. Microsoft deliberately forced vendors to sell Windows-only systems by threatening them with severe price hikes if they packaged OS/2.
That is anticompetitive, and they were excellent at it. Apple always wanted a curated store and have deliberately structured their store for this reason.