"But, not being a v techno type, is it unreasonable of me to expect the computer to have been so pre-programmed as to deliver exactly what it says on the tin, without my having to make my own way-beyond-my-abilities-and-understanding adjustments to get what the specification promised me from the off?

Yes. It is doing what it says on the tin, this is operator error. The spec didn't say it could read your mind, and the spec on my bouzouki didn't say it'd play all the chords Donal Lunny does without some input from me. A computer's a tool and it needs to be learnt how to use it like anything else. Your issue isn't with Apple, it's with any computer.

What applications are you having a problem with? Feel free to PM me and I'll help if I can as this represents rampant thread drift of the most heinous type :-)