Apple wants to lock you into their market and does so by locking down the platform. If your a fan of free markets, this is going in the opposite direction. A user or a publisher can choose that a 30% "tax" on a transaction (Apple's cut of App Store purchase) is ok but locking you in so that as the market grows you have no choice but to pay the 30% tax is not ok; it violates basic tenants of free market principles.
Apple has a great product today, but going against a free market generally ensures they are likely to not provide the best product/store/platform in the future.
I'm a fan of free markets when they're beneficial to all involved, and in certain cases even when they're not. Even though Apple's model isn't free, I still see it as beneficial to all involved.
Apple's "tax" provides resources and a revenue stream to cover everything from documentation to hosting the free applications. It could also play a part in driving the prices of the phone itself down. It also gives it clear bragging points which it's used quite successfully.
The user benefits from the applications, and one could assume the lack of clutter/meaningless/duplicative applications within the store itself. They also benefit from the "full product" phone->store->apps->payment ecology.
The developer wins because they get to develop towards a product that has a great feature set, an ecology with paying customers and momentum in the product itself.
Windows, Blackberry, Palm et all have all had ways to work with previous products before the IPhone without issue, under the free market approach. No true central registry, no payment ecology, and hasn't gained anything from it directly. Now android is in the mix, and as far as the payments goes, it's not looking too pretty from what's being put out there so far, but it's early yet we'll see.
I'm not defending Apple, I don't even own an Iphone (BB user, contract about up, going to N900). But when someone sits as a developer and continues to blast Apple because it's not open enough (when it's never been "open enough" & when you look how "open" phones before it were...) - it honestly baffles me. If they don't want the Apple "tax", don't play. Through Itunes/Ipod Apple has done something no one else has really done on the web, got users to pay. When the other companies can do the same thing, then we'll see how they do down the road.
Essentially I keep thinking of this. The Texas State Fair rivals as one of the biggest in the United States and doesn't look to lose that anytime soon. It operates in the same persona as Apple does. It selects by committee through applicants on who can be there, you pay a tax (rules, and fees) on how to operate. However, there's a ton of paying people there, so you deal with the rules at hand, because you're getting "fed".
It may not be free in the purest of sense, but griping after going in knowing full well it isn't is idiotic IMO.
Developers don't benefit from having an all powerful middleman inserted between themselves and their users/customers. It's not that Apple just makes the rules. They don't even bother to make proper rules. They just rule.
But you're right, contrary to being born as a subject under some absolute monarch, I can make a choice in this case. My choice as a user and as a developer is not to accept the kind of nasty middleman structure Apple is perfecting.
Apple has a great product today, but going against a free market generally ensures they are likely to not provide the best product/store/platform in the future.