Aaron86: I understand the rest of your post with regards to watered down gameplay, DRM, and DLC, but I take issue with how you put Wii-like interfaces in the same sentence and paragraph. Such interfaces wouldn't be appropriate for every game, including many of the games we on GOG are likely interested in, but I wouldn't say they're a cause or symptom of poor game quality.*
Your issue is fair. Motion gaming is not nearly as bad a problem as the other issues which I mention. In theory, I have no problem with motion control. My problem is that the execution, thus far, has tended to be gimmicky and clunky in the vast majority of titles, at least in my opinion. Red Steel II and The Conduit's controls are good, for instance, but they still do not reach the zenith of keyboard/mouse and gamepad control schemes. My experience with these sorts of controls is that novelty often trumps solid gameplay in the consideration of those who are putting together games that use these assets. Part of this is that developers just aren't used to the motion control paradigm and how to design games with those controls in mind. Until motion controls can become consistently solid and hold their own against traditional schemes, I still call them a drag on the quality of current gaming (although I realize they bring about new sorts of gaming which do not fit my own, more traditional model of gaming, and that they do, in fact, have potential).
Perhaps I ought to be more forgiving, but I'm sure we can agree to disagree.
I would also like to add that I agree wholeheartedly the assertion of yourself and Stinging Velvet that the angst being experienced by gamers today is a direct result of the current polarity of the gaming market place between the new casual games (exemplified by mobile apps, Facebook games, and motion minigame collections) and traditional games. The problem is that the marketing view you describe is the one with all the power (read: money) in the industry and is the one calling the shots for AAA titles which need huge piles of cash to develop.
These two poles can and should exist in the industry, but they ought to be more or less independent. What we are seeing, currently, and what is causing so much of a stir is a hedging of bets by publishers and developers to find a centre which really isn't there, a route which leads to failure. Take Dragon Age 2, which was simplified to appeal to a greater portion of the gaming market (viewed as homogeneous body by the industry) resulting in a dramatic decrease in quality (also the result of a short dev cycle, but I still say the problems were there based on the "streamlining" which was planned from the start). The end result is that it has failed miserably in long-term sales after an initial surge at launch, a surge based on the reputation of the unabashedly traditional Dragon Age: Origins.