POD has hardly changed during the last 2 decades as well, right?
POD didn't even exist 2 decades ago. In fact, POD is less than
a decade old, it came with perl5. And, given what's going to
happen with perl6, I wouldn't want to bet money on "POD will
not change the next decade".
Besides, all POD tools are written in Perl. Having to install
a dinosaur like Perl just to be able to deal with general documentation
doesn't rock - it sucks. It's hardly any worse than requiring
people to install Word or some other tool that reads Word format.