What do they leave to be desired? Style is a personal preference, of course - but merit? Every single djb implementation I've seen (a lot of them) is fast, efficient, secure, and clear, once you get his style.
Mostly his disregard for packaging conventions and unwillingness to acomodate them. The code is usually A grade, but the odd use of the filesystem, runtime configs, daemons etc. means it will never get into any mainstream distro without heavy patching.
There's a reason why libsodium's tag line is "P(ortable|ackageable) NaCl-based crypto library".
The word of distros/packagers isn't gospel, but it counts for a lot, considering that (for better or worse) most people won't even think about using something not available as a package.
I've been doing "apt-get install daemontools daemontools-run" since forever on Ubuntu; it might take a little longer to get into the repositories, but it does get into mainstream distros with almost no patching -- comparable, IIRC, to packages of similar size and complexity that do not have an upstream debian packaging.
