For what it's worth, at least one member of the glibc steering committee appears to agree:
"I agree with removing this joke. A bit of humor is fine - indeed, the manual could use a bit more than it has - but this attempt at humor does not work. The manual should be high-quality, and that includes high-quality jokes."
"I agree with removing this joke. A bit of humor is fine - indeed, the manual could use a bit more than it has - but this attempt at humor does not work. The manual should be high-quality, and that includes high-quality jokes."
https://sourceware.org/ml/libc-alpha/2018-04/msg00604.html