I wonder if it is an instinctive reaction to the common complaints (no, relatively, easier packaging or installation routes) to djb softwares. It was previously seen in TweetNaCl [1] which is arguably an irritated response to libsodium [2] which in turn wraps djb's NaCl library [3] in the way djb considers suboptimal [4]. djb is known to be not very interested in the modern packaging systems or practices, so it might well be his way to protest them.

[1] https://tweetnacl.cr.yp.to/

[2] https://download.libsodium.org/doc/

[3] https://nacl.cr.yp.to/

[4] Page 3 in https://tweetnacl.cr.yp.to/tweetnacl-20140917.pdf