"the kind of people using two-decade old software when more modern alternatives are availble are so stuck in their ways, you can't expect them to upgrade anyway"
Broadly, I agree with this. However, let us assume the following: -
Risc PC Owner,
Running RISC OS 6
Running Podules such as a SCSI Card and a TV playing one
Perhaps the user has both modern version of some software but then also has lots of old utilities which are used on a regular basis.
If ROL suddenly decided that all the next release of their version will be 32bit only, then why as a user of the above hypothetical system would I want to upgrade it if large number of apps and my podules will no longer work?