That's because I (the author) still work on it alone and nobody wants to contribute. I receive tons of e-mails that go like "when will it run XYZ", but practically no pull requests.
For what it is worth, that is from personal experience. I went through the trouble of re-licensing a script with consent from all contributors from GPL-2 to BSD-2 in a package in the past because of harassment from armchair legal experts. It had been mistakenly marked GPL-2 when it should have been BSD-2 to match OpenRC. It had been included with binaries under the CDDL. There was no incompatibility and the GPL FAQ even talked about the case under mere aggregation, but that did not stop the harassment from the stream of arm chair experts rushing to tell me that I had committed some egregious offense for having the package marked both GPL-2 and CDDL. Relicensing the script to the license it should have had in the first place put an end to it and created one less GPL licensed thing in the world.
Anyway, switching to the LGPL now would be easier than switching later. It only gets harder as a project ages because you start to lose contact with past contributors.
I also want to avoid the inception of businesses providing enhanced Darling for money without releasing the full source code (think Cedega), because in my view, that's akin to a fraud committed on other developers who invested considerable time and didn't ask a dime for it.