I sympathize with that attitude, but I cannot guarantee an employer or my customers that the owner won't be made aware by some goodie two-shoes.

I'm not saying you shouldn't ever use copyrighted material without permission. Actually, my view is that copyright is stupid and needs to be abolished, and that the entire purpose of FOSS licensing is to protect against the quirks of copyright and actors powerful enough to abuse them. However, just because you can (and arguably should) pirate copyrighted material doesn't make it always a prudent choice.

I am an anarchist, so I'm not interested in complying with the law for its own sake. However, I am interested in how the (thugs who enforce the) law could clamp down on me or my customers for reusing other people's work. Unfortunately, that requires either using FOSS, or going through the dog-and-pony act of setting up a licensing agreement. It is absolutely plausible considering my field that an employer might force me to use proprietary software or even allow my product to be proprietarily licensed, as much as I loathe proprietary shitware.