Alan, frankly it's a plague on all their houses. Coordination in this industry can be pretty dismal and the blame can be distributed all around. But much grief could be avoided if there were a standards group to which all the major players belonged having rules or guidelines about upgrade processes, information sharing and the duration of support to legacy items. Right now it's a jungle with each company doing as they see fit to maximize their own commercial interests.
Companies need to balance their short term interests (make people upgrade) with long term interests (not pissing off their customers enough to get them to switch brands).
In the Windows world there are roadmaps for future development, and their is compatibility with legacy software.
With Apple, there has been no official announcement of when Rosetta will be going away, although everyone believes it will be next week.
With Windows, it's generally a safe bet that you have many years to recoup your investment in a printer or software package.
With the Mac you'd better be able to justify that investment in just a few years, as it may no longer work after that.
It's quite true that there is some software or hardware that you expect to replace every year. When the core technology for your business is rapidly changing, it makes sense to upgrade frequently to stay on top. It does not make sense to replace working support infrastructure (there is no need for me to replace my office chair every year in order to get the new model).
We don't need standards groups, or regulations to solve this problem. We merely need to alter our purchase patterns so that it is in the financial interest of these companies to maintain support.
If legacy support is important to you, then when Lion comes out, don't buy it, and fill out a comment form on Apple's web site letting them know why.
If you want printer driver support for older printers, then tell Epson that you won't buy a new printer form them, unless they show their commitment by providing drivers for older hardware. An Epson 7900 or 4900 printer isn't cheap. You might want it to last a few years. If you think the changes in Lion are big, you haven't seen anything yet. Mac OS-X is converging with iOS. I think it's a pretty safe bet that after Lion, all printer drivers will need to be re-written and a lot of printers are going to be left out (unless you are happy with generic GIMP print drivers).
Remember, Microsoft and Apple are businesses. If we reward good behavior by buying their products, and penalize bad behavior by shunning those products, they will get the idea pretty quickly.
Keep in mind that the underlying root of this discussion is that Apple, a company with tens of Billions of dollars of cash in the bank, is likely to drop support for Rosetta. A move that will annoy and inconvenience millions of customers. Some have defended this as a licensing issue. I find this difficult to believe as Apple could likely buy the division that owns Rosetta, license itself the technology, and then sell off that division.
This is not a technical decision on Apple's part, it is a market decision. They believe that consumers are better off junking old software and buying new. If you agree with Apple, you should upgrade to Lion. If you don't agree with Apple, then perhaps you shouldn't buy the upgrade.
For me, I want to be the one who decides when the time is right to upgrade my software. I don't want an outside company (like Apple) making that decision for me.