It seems to me that some of the desire for a "perpetual license" comes from forgetting what happens when one buys a new camera, and wants to open the raw files in ACR (without converting to dng), or what happens when we buy a new computer with a new (and different) operating system, and all-of-a-sudden you need software upgrades.
Actually, I agree and further wish to reinforce the idea that a whole bunch of the desire for perpetual licenses comes from this very upgrade treadmill. In the digital age not only is there a value in "archiving" old software versions, for many of us there is a need to archive old hardware as well. I swore I would never do that, but perhaps ironically, Adobe was the first company that forced me into both a software and hardware archiving strategy. I had been using Aldus Pagemaker for many important documents including my Master's thesis. Then Adobe bought Aldus, soon after canned Pagemaker, and offered an upgrade pathway to InDesign. I did migrate to Indesign, but I soon discovered that the pagemaker-to-Indesign conversion software offered by Adobe was half-baked. It left considerable errors in the page layouts that needed to be handled manually on a page-by-page basis. I just didn't have the time to go through a huge number of files one by one, so I "archived" a complete software/hardware system that can run those old documents. I know that approach also won't last forever, but it's still working a full decade after those pagemaker files would have otherwise been orphaned. In this passage of time, I've been able to discern which of those files really matter to me in the long run, and those are the ones I am now taking time to migrate painfully by hand to newer systems. My latest hardware legacy issue was forced by Apple. Apple orphaned the Rosetta emulation software that allowed older Power PC software to run on the new Intel Macs when OSX 7 (Lion) was introduced. Apple's argument was that all software developers had been given plenty of time to migrate their products to the newer OS platform. However, some of those software vendors saw this Power PC-to-Intel transition as an opportunity to radically overhaul and/or abandon some of their older software and thus force customers onto new software that perhaps inadvertently orphaned various features of their own older software. This situation thus became a real catch-22 for the end user. Personally, it left me with quite a number of mission critical pieces of software that won't run on my latest Macs. So, I keep asking friends and family for their older Macs, and now have a small fleet of them... running OS9, OS10 tiger, leopard,etc. Everything's working fine, but again no doubt not forever. Yet I've been able to keep all of my digital files accessible long after the manufacturers have in effect said, "get over it, it's not our problem anymore".
So, let's consider the traditional "subscription model" from hardcopy print. You buy a hardcopy magazine subscription. You get new and different hardcopies with new features (i.e, articles) each week, month, etc. You stop your subscription. The publisher doesn't ask you for the old articles back. You still get to use what you bought. This approach also needs to be the model for digital subscription as well. Obviously, Adobe wouldn't want folks buying one low rate introductory month, then dropping immediately while keeping fully functional software, and then resubscribing say two or three years later to repeat the same abuse. However, the answer to that problem lies in a contract where one agrees to an optional cancelation fee that would be comparable to an "option to buy perceptual license copy" price for the existing software on one's computer which should then remain fully functional, for example. In effect, the option to convert existing subscription software to perpetual license for a reasonable price is the sensible solution to this dilemma.
I think Adobe will get there, reluctantly perhaps, but it will only get there once the managers understand the scope of the problem and why many current customers are worried. In the meantime, we need to keep the pressure on Adobe so that it figures this whole digital subscription model out in a way that works for Adobe as well as for all of its customers, not just those "preferred" customers who justify subscription costs on the basis of the money they make this month using the latest version.
cheers,
Mark
http://www.aardenburg-imaging.com