Funny. I've had nothing but success with DLNA in my home. In fact, my reciever is so easy to interface to, all my kids end up sending music directly to it when I'm listening to something they don't like. (however, this behavior stops when I threaten to take away their wifi access). I turn on my windows 7 computer upstairs. that's it! My Samsung blue-ray, sony PS3, my marantz receiver, and all our phones and laptops can access it. The thing that mucks it up is Apple's insistence of having their own stupid connection scheme, I presume because they want us to buy one of their Apple TVs?. No thanks.
The problem is that arguments can be made for each device to be king of the hill. Historically the receiver was the center of the audio system, so they assume that the same should be true when they are attached to a TV. TVs have long been the primary interface, but they got blindsided by set-top boxes and are rapidly trying to regain that position by integrating apps and providing more compute power (the latest wave crows about containing multicore CPUs - how am I supposed to evaluate that as a consumer?). Any technical argument about which is the "natural" center of the system gets swamped by marketingspeak from vendors desperately trying to be seen as the leader in the space.
Personally, I would prefer each of these devices to provide a standardized network-based control interface that also provides device state. This was never really possible with IR remote contrls, but anymore most devices have Ethernet or Wifi so that is no longer an excuse. DLNA could be that interface, but they have to get serious about supporting it.
Once that is in place then they can also provide a user interface. There is still room for user confusion, since there will be a need for a user to decide which device they feel most comfiortable interacting directly with, but at least any of them would work. It would also open up a market for truly next-generation remote control capability. We are starting to see apps for tablets and cell phones along those lines, but there are still not enough devices that provide the control interfaces for this to really take off.
DLNA is a very interesting concept. I have at various times tried to get my DLNA devices to talk to each other, but I have found the process to be laborious and generally not worth the effort. My impression has been that pretty much every device wants to be the controller rather than providing an interface by which it can be controlled. This is not unique to DLNA, but it does subvert the interoperability that DLNA tries to achieve. Is the TV the center of the living room? Not according to the receiver manufacturers. This is also contested by the set-top box manufacturers and the game/media system people.
At some point I would hope that each of these devices would put effort into a backend control interface. Each of these devices should be perfectly capable of acting as a peripheral instead of trying to force the user to put it in the primary position. If they want to also provide a primary control interface, fine, but it also should play nice with others.