May I suggest you read the quote in context before bashing him: Mike's post?
The word TAX has a lot of implications...and I disagree with the concept. I think it much more a cost of doing business and should be viewed in light of what sort of return you will get from your investment.
Nobody is holding a gun to your head making you (or anybody else) upgrade to Adobe's latest release of Photoshop. When CS4 comes out, it doesn't magically make your version of CS3 quit working. The only thing that really happens is that when the "next version" comes out, free updates and bug fixes cease for the old version. To a certain degree, that may lower the value a bit of the older version–depending on the way you look at it.
But some people have some pretty perverted ways of viewing situations. Photographers have this tendency to view intellectual property as somehow less valuable than tangible property–even though the profession of photography is dedicated to creating intellectual property. Photographers don't seem to have the same level of irritation when Apple or Dell announce brand new super charged computers or Nikon and Canon come out with new bigger MP cameras. Oh, there's grumbling, to be sure. But not in the same vein as the bitching about Adobe coming out with a new version of Photoshop and complaints about the "Photoshop Tax".
It seems that many people wish the software would be frozen in time and offered with a life time license and perpetual free upgrades. That same level of expectation isn't there for hardware. Compare that attitude with a photographer's client when they think that they should "OWN" all the rights to a photograph that they "BUY".
And that's an irony that I don't enjoy (since I engage in both the creation of software and the creation of licensed images).