The only issue with your thinking is that some people STILL have problems with such services and/or have a bad taste in their mouths from previous experiences with these and other services or DRM in general. These people are going to be extremely difficult to appease. Also, your conclusions are actually unreasonable from the sense that, for one, people are creatures of habit. Just because iTunes and Amazon have made music downloading easier, doesn't mean that it is an easier process for those that are already pirating, nor does it mean that it will be enough to immediately pull all of them to a new method of downloading. For that matter, I think that many Americans (and expecially non-Americans) are extremely fed up (I know I personally am) with the media and content companies' antics and are waiting for a kind of concession of sorts or an ACTUAL boon to bring them back in the fold. Even those people that I know that abhor downloading and/or even burning backup copies of your own CDs or DVDs are bothered by media and content companies' money grabbing attempts. Many of them don't know what to do, some want to fight back, and some just try to be legal for now, but the point is that the number of disillusioned customers is growing rapidly. This is also a possible contributor to piracy numbers.
Most importantly, it is important to consider the sources of your data. Most data that I have seen quoted in regards to rampant increases in piracy has been funded and compiled by sources with either funding or links to groups who have much to gain from such numbers. While not entirely disregardable (pretty sure that was a coined word there), I still am loathe to automatically take such data for granted, especially considering some of the creative methodology that has been used for the past years to evaluate sales lost through pirating. On the other hand, I really haven't even seen (so far) any studies pointing to significant increases in piracy from independent companies. Basically, I still feel that we (the general populace) are still rather uninformed between the conflicting reports and the biased information we receive, unable to RELIABLY make any determination whether or not piracy is increasing or whether the losses are even legitimate, especially in a booming industry (the music industry is actually growing quite well right now...only middle-man industries are suffering a downsize - hence the outcry of the recording industries).
Honestly, when it comes down to it, I really don't know whether your conclusions are CORRECT or not, but I don't think that you can reasonably or reliably conclude such things...yet.
However, I do believe that individual freedoms are being constantly revoked for the sake of these conglomerate companies and THAT irks me quite a bit. Perhaps the important questions aren't even about piracy at all, but about the loss of freedoms that is taking place in the efforts to fight terrorism and piracy.