I would expect both the printer vendor and the computer vendor to realize that I am its customer, that I have spent a good amount of my monehy to purchase their products, and that it is not unreasonable to expect to be able to use them for more than a year or two. I would expect them to work together to ensure that reasonably current products are supported (0-5 years old), and more if possible.
If they don't want to provide new drivers then I would expect them to give the specs to some 3rd party operation that would be willing to write the drivers. i would pay the 3rd party for the drivers. But, I would also be very disspointed that the manufacturer chose to not provide the support.
If you want your computer investment to last a long time, you should consider this when choosing your platform.
If you always upgrade your computers at every opportunity, and always upgrade to the latest and greatest, than either Mac or Windows will work.
Perhaps you have some software that you use rarely, and don't need the latest version. Perhaps you have a very expensive printer and want it to last five or ten years. If you fall into this category, you should research the policies and track histories of the platform before investing.
With Apple, there are no published policies. Apple has been issuing security updates for both the current and one previous version of the OS. They have made no commitment to continue this. Apple has no published policy on how long software or hardware will be supported, and has been known to discontinue technology without any advance official notice. Apple also has a history of aggressively eliminating outdated technology and embracing new technology. New Macs won't run older OS versions. When you replace a Mac, you may be forced to upgrade a large percentage of your software.
For many people, Apple's behavior is a good fit. Others find that they need to update hardware and software far more frequently than they like.
The Windows platform has a different history. Modern computers can run old operating systems, and new operating systems can run old software. If you want to run old software, the Windows platform is more likely to allow this.
Again, for some this is a disadvantage, and for some it's an advantage.
Of course, this isn't the only difference between the two platforms. Any rational decision should take the other factors into account as well.