What’s so great about open access?

So let me start out with a caveat: I only understand open access from the “regular person” point of view. I’m not an engineer or a Washington insider, I’m just some guy who has a cellphone and is relatively knowledgeable about the industry.
That said, I just don’t get the whole open-access thing.
On one hand, I like stuff that’s “open.” I like stores that are open, I like doors that are open and I like people who are open. So when open-access proponents make arguments that the cellphone industry should be more “open,” I’m inclined to agree.
However, once I start trying to put the open-access concept into realistic, everyday situations, I quickly become less-than-thrilled about it.
For example, open-access proponents argue that carriers should allow any device and any application onto their networks. But right now, with a wireless PC card and a laptop, I can pretty much run any application out there. And that wireless PC card will fit into any device that accepts it. What’s not open about that?
Based on this observation, I can only guess that the open-access argument is supposed to apply to cellphones. But again I’m a little stumped: Carriers that support Java phones allow users to download most Java application from any developer. Carriers offer general warnings about such activities, but the process is still possible. And there’s some useful Java apps out there that work under this model-Google Maps for Mobile and Opera Mini to name a couple.
So my point is that, based on these examples, one could argue that the open-access paradigm is already at work in parts of the wireless world.
But I understand that the current methods of open access don’t necessarily meet with the spirit of open access as bandied by supporters. They’re talking about any device, and any application.
However, I’m not so sure this is such a great idea. Just like any other communications medium, wireless is finite. There are finite capacity and finite resources on which it can run. So if any device is allowed to run any application, regardless of the capacity and resources used, the medium may well be stretched beyond its boundaries.
And if that theoretical situation occurs, I might not be able to make a call using my cellphone. And I’m not paying $100 per month for my cellphone service so that some other guy can jam up the line.
Indeed, one could argue that the open-access paradigm logically leads to a pay-to-play model, where the user who pays the most money will get to use the greatest slice of bandwidth. And I’m pretty sure those who tout “openness” as a positive principle would not want to see poor people pushed out of the wireless revolution.