Your logic is flawed here. First, software has economies of scale because it's easy to produce the second copy of a program once you have the first one. It has nothing to do with lines of code.
Second, buggy software being better than no software would still be true even if bugs were super-linear in the number of lines of code.
I'm pretty sure that bugs aren't sub-linear. As you pile on more and more lines of code, the number of bugs per thousand lines goes down? The code gets better as you create more and more of it? Experientially, no.
I think it's super-linear, for a couple of reasons. First, the bigger the program, the bigger the team. The bigger the team, the more below-average coders on it. Second, the bigger the program, the more room for weird interactions between obscure conditions.
No, it's definitely not sub-linear. Bugs per line of code do not decrease as you have more lines. I suspect it's