One of the great things about Adobe(even though CC has them on my "not nice" list) is that they've pretty much always gone out of their way to milk all the performance they can out of a particular architecture. Back in the PowerPC days, this was especially true, and Photoshop/InDesign/Illustrator were the "gold standard" programs that would actually noticeably run faster than the x86 counterparts when released. Photoshop 6 is even the only program I know of that will actually use both the processors in my 9600/200MP. In the OS 9 days, Photoshop would also use the second processor in a dual processor G4 system-something that OS 9 itself wouldn't do.
I think there's a good reason as to why Apple use to run Photoshop comparisons on stage during keynotes.
I think there is a certain amount of truth in your argument, but I would also argue that some of that came down to profit margin.
Adobe, like all software companies, are constantly working on the next version of it's application because there's only so much profit to be gained in the current version. But there are only so many things you can DO, only so many 'features' you can create out of thin air and make people realize that it's something they can't live without.
Constantly working to make the program run better, faster and more efficiently is something that users will pay for. Combine this with Adobe's domination of the design industry and Adobe can charge pretty much whatever the hell they want - and people will pay it. They'll pay it because it makes the program use their computer more effectively or they are convinced that the program has a feature they must have.
And Adobe makes money - again.
We are lucky in the US, because Adobe just crushes designers with VAT in the UK. One of my Aussie friends had to browbeat his vendor into charging him the same prices in $AUS as the US because he wasn't willing to pay over $1000 more for the same thing we get here.
And now with their whole update subscription thing, Adobe gets even more.
Don't get me wrong. I appreciate what Adobe has done for the industry, but a lot of it has to do with profit.
I think that may have been part of the undertone of your original post, but I'm kind of bringing it more to the surface.