You're actually making the case for licensed software without free distribution here -- the plumber has worked on your house, and possibly installed parts, just

You're actually making the case for licensed software without free distribution here -- the plumber has worked on your house, and possibly installed parts, just as someone may work on a computer, and possibly install software. If you want, you could remove those parts and sell them to your neighbour, but then you wouldn't have them anymore. Or, you could sell the house whole, just as you could sell a computer with software installed (okay, peculiarities of licensing may make that challenging, and I'm in favour of licensing reform). But what you can't do with plumbing work is have it performed, then copy it to your neighbour's house whilst still keeping it for yourself. You can do that with free software.