To use a mundane example of what I'm talking about:
If I'm one of two bakers in a town and I make tons of great bread for the week, while the other baker ruins his batch for the week, I'll likely be able to charge whatever I want, being the only game in town that week. If I decide to charge $50/loaf, when $2/loaf was standard, I can go ahead, as long as people need the bread enough to buy it. There is no 'check' left in the market in the absence of competition other than consumer behavior.
In any event, the absence of a 'check' on my behavior does not make it 'moral'; it simply means no one can 'check' it. My power in the market to set my own price is unchallenged. That does not make my decision inherently a 'moral' one, no matter what my choice. If I push the families in my town to the brink of poverty, simply because I can, that isn't a 'moral' choice.
Having said all of that, nVidia is not doing that here. The GTX was launched at a price-point that has been seen before (if not by much), so this is not a case of finding out that one has no competition and then gouging consumers. It's a case of there being no competition-inspired downward pressure on pricing.
The real reason I made this analogy is to clearly articulate that the absence of a market 'check' on my behavior is not the only moral litmus test whereby a company's (or a person's) behavior in the market is to be judged. Transferring the moral culpability for 'checking' my behavior in the market to my competitor is thus a ridiculous suggestion. Certainly my behavior is affected by my competitor's, but my competitor's behavior--good or bad--does not absolve me of responsibility for my own.
Again, in this particular case, nVidia is doing just fine in my book. This is not some underhanded bash on the company. If they took this opportunity to start increasing prices on their shipments to vendors, then I'd be upset, but I highly doubt that is going to happen. We might see some of their vendors slowly increase prices, but time will tell.
It's ridiculous to 'blame' nVidia's actions on AMD, just as it is to assume that a lack of downward pressure on pricing equates to price gouging.