I think it's easy to say they missed a trick now. At the time, Acorn felt like a tarnished brand - with all the (relative!) optimism around the market at that time, people felt they wanted something *new* and exciting.
Personally, I think the whole situation with ROL/Castle missed a trick, and probably spelt doom for the platform - we needed one company developing RISC OS. But maybe that's a discussion for another time.