Why LGPL when the original license is more permissive? (https://sourceware.org/bzip2/manual/manual.html)
bzip3 is not made by the same author as bzip2, that's why there is a licence disparity.
Please stop questioning people's choice of license.
If you don't like it, you're entitled to not using it.
bzip3 is not made by the same author as bzip2, that's why there is a licence disparity.