> I don't care about the products we build for someone else (why should I?)

I mean, this obviously depends on the kind of product - is it some biotech to make someone's life better, or is it a gambling website tuned to suck the most out of whales? As engineers we're much better placed than most people to do something meaningful with our work, and sticking with a job where you don't see that value is a pity. But if you just don't care about building something for someone else... maybe you should change that? As you say, there's little choice in whether you have to do it (unless you win the lottery or something), why not make a goal out of it and get some enjoyment out.