Yeah, I haven't seen SourceMaps used used as much as it should, but that's
probably because of it being a fairly new technology.
From experience, I try to minify my JS files as much as possible on a live
site for the file size. If I want to make the source available, I put in a
SourceMap link to the unmodified JS file with the source file having some
license headers.
The majority of developers don't know or care about having a license for
their JS files. If they do know a thing or two, they intentionally make it
non-free in a worry that a competitor steals the code.
