Given that the comments never made it into the
compiled code, there was no
space reason to omit comments. There must have been
another reason.
Attitudes in software engineering have changed a lot over the 60 years we've
been programming. Actually, UNIX was better than a lot of OS sources
I've dealt with. Further, you had disk space and compile time issues to
worry about.
Amusingly, I worked with Mike Muuss for years (first at JHU and then at
BRL). Mike believed much in putting comments on everything. The DMR
"You're not expected to understand this" comment incensed him so much (yes
I
know that's not what DMR meant) that he wrote an entire page to explain just
what retu/aretu/setka6 were doing there.
Amusingly, Mike was further incensed when Mike submitted a bunch of
revisions to BSD and McKusick, in the name of maintaining a uniform
commenting style, deleted all the comments.
I guess NONE is pretty consistent.
While this next anecdote strays from UNIX, I worked on a project my first
job out of college on a database system written in Fortran and Macro 11 on a
two-system RSX-11M+ system. One of the early projects there was to write
a program that counted "lines of code" to report to the customer progress or
something. The head of software came up to the head database programmer
(not me) and said, "Do you know that we ran our line counter on your modules
and it said that there is only one line of comments in your entire module).
Jerry pointed out their software had to be in error, there weren't any lines
of comments. In fact, a closer examination noted it counted one of the
MACRO-11 directives (.TITLE or something like that) as a comment. In
Jerry's defense, there were comments in the code, just not lines that were
only comments. They were just put at the end of the lines of existing
instructions.