I drive a little Toyota hatchback. I do so because I got it relatively cheap from my sister-in-law. This was possible because she owned the car, [instead of having] a non-transferable license to use the car under certain conditions.
I know how to pump up the tyres and refill the thing that squirts water on the windscreen. That's all I know about maintaining the vehicle, and probably all I ever will know. I take it to the local mechanic of my choice every couple of years and he fustigates the Smoot-Hawley flanges or whatever for me, at what I can only assume is a reasonable price.
I am very glad that the bonnet was not locked shut at the factory by Toyota, and that there is not a Drivable Motor Vehicle Act (DMVA) to make it a criminal offense for anybody to attempt to service their own car, or pay somebody other than the manufacturer to service it. I may not personally know the first thing about its [sic] inner workings, but if I suspect I'm being charged to much for some work on my car, I can go a few hundred metres up the road to the next mechanic who can provide me with a quote.
Most of these mechanics probably chose this trade after opening up the bonnet of their own car and having a playful poke around, the same way I learned how to program computers. Now as Richard Stallman would say, the ethical issues around car manufacturing and software manufacturing are not the same; I don't have the legal right to make a perfect copy of my car, but that's okay because I don't have the practical means to do so -- no matter how much technical skill I am able to acquire, and neither does anybody but very large corporations, so losing that freedom (through patents) doesn't cost me anything, while potentially delivering the benefits to society that the patent system [for car manufacturing] is supposed to provide.
But if somebody paid me to write some software for them and I said "okay, I'll write it for you, but only under the condition that you don't copy it or attempt to fix or improve it yourself, or pay somebody else to fix or improve it," that would be a very bad deal for the customer, because the means to do these things are so cheap that you are practically only paying for the time of the person who does the work (or not, if you do it yourself). It would be such a bad deal in fact, that if I managed to convince a sucker to fall for it, I would have to regard my own behaviour as unethical.
Granted there aren't as many programmers as motor vehicle mechanics in my town, but that can and should change. Already I can point to half a dozen people I know who could (and hopefully will) become as familiar with the inner workings of [the free software package] Drupal as myself with only a little effort. As this begins to happen across a wide range of software the real cost of proprietary software (as opposed to the mere price tag), and the benefits of freedom, will become apparent to even the most non-technical users.
Speaking of "tryes", "metres" and "bonnets"; the end software patents campaign needs help documenting the patent issue in Australia and New Zealand, among other locales.