So Apple's monopoly over a part of their own great product is threatening Adobe's monopoly over a part of the whole Web based on a crappy product. Let's not shed too many tears here.
I don't like the lock-in in Apple products, and don't use any, but I'm loving that finally someone is pushing back on Adobe for all the harm they've done to the Web.
If someone is not satisfied with Flash, they can go ahead and build another Rich Internet Application Plaftorm, as Microsoft is doing with Silverlight and Sun is (was?) with JavaFX. So everyone can, in principle, have access to the part of the Web that Flash "conquered". It is hard, but possible.
Apple, on the other hand, is the one true gatekeeper that ultimately defines what runs in their systems. You can only have access to their platform by abiding to their terms. They are just impossible to bypass.
Apple is a gatekeeper to their platform, as those other companies mentioned are gatekeepers to their own platforms...as Adobe is a gatekeeper to their own platform. It is not impossible to bypass any of them. If Apple decides that they don't want you pissing in the shallow end of their pool they can ask you to leave; you can go swim in someone else's pond or you can get yourself a shovel and start digging your own, but there is no monopoly involved here at all.