I would tend to concur that needing 2 systems means one is lacking in functionality. Or perhaps it is simply lacking in the ability to generate and read file formats from other platforms? There's still nothing on the Windows platform to rival TechWriter, so functionality or lack of is all relative.
I've come to the conclusion that RISC OS can now never be a major computing platform for the casual home user. But I still believe it's excellent for people with specific requirements and for which RISC OS software exists to fulfill those requirements.
I've often thought that RISC OS would be suitable for industrial control with some appropriate bespoke software and hardware. Most large installations will use a DCS using proprietary hardware such as Honeywell (if you think RISC OS hardware is expensive, try buying a keyboard from Honeywell...). However some systems such as ABB use software running on a PC platform. Not fun when you lose control of half your plant...
For small to medium concerns, RISC OS would be ideal and the sales would generate some revenue to help advance the platform for desktop users and provide useful employment for developers.