> I highly doubt that male chauvinism/sexism/harassment is the
> reason women aren't going into tech careers.

> How would you explain that there used to be more women than men
> as programmers?

The women who went into "programming" back then for the most part played a role somewhat similar to the role a compiler does for modern programmers, and so the fact that it seemed like an attractive role to some women of that era has very little bearing on its appeal now.

At that time "programming" meant the relatively unskilled job of translating someone's detailed pseudocode onto punch cards or worse. The need for such unskilled labor diminished as the abstractions and automation improved. Ensmenger speaks for himself about his research on this in the following article:

Goldstine and von Neumann spelled out a six-step programming
process: (1) conceptualize the problem mathematically and
physically, (2) select a numerical algorithm, (3) do a numerical
analysis to determine the precision requirements and evaluate
potential problems with approximation errors, (4) determine scale
factors so that the mathematical expressions stay within the fixed
range of the computer throughout the computation, (5) do the dynamic
analysis to understand how the machine will execute jumps and
substitutions during the course of a computation, and (6) do the
static coding.

The first five of these tasks were to be done by the "planner," who
was typically the scientific user and overwhelmingly was frequently
male; the sixth task was to be carried out by coders.

Coding was regarded as a "static" process by Goldstine and von
Neumann -- one that involved writing out the steps of a computation
in a form that could be read by the machine, such as punching cards,
or in the case of the ENIAC, plugging in cables and setting up
switches. Thus, there was a division of labor envisioned that gave
the highest-skilled work to the high-status male scientists and the
lowest-skilled work to the low-status female coders.

As the ENIAC managers and coders soon realized, however, controlling
the operation of an automatic computer was nothing like the process
of hand computation, and the Moore School women were therefore
responsible for defining the first state-of-the-art methods of
programming practice.

http://womensenews.org/story/books/120323/women-were-first-c...

This one story -- about a small group of women chosen for their exceptional capability as human "computers" who previously calculated by hand numerical tables like the ones the ENIAC was designed to calculate -- has been spun into a narrative suggesting that women dominated early software development. Nothing could be further from the truth, and I don't think Engsmenger sees it that way. He says elsewhere that "Although many of the earliest programmers were women, by the beginning of the 1960s programming was generally considered a male profession. Certainly the elite ranks of ‘‘systems men’’ [i.e., those responsible for what we would today consider software design] were, quite literally, men." http://homes.soic.indiana.edu/nensmeng/files/ensmenger2003.p...

Of course, all of this shows that male chauvinism (and very very very probably harassment too) has always been a huge problem for women who wanted to participate in this field, but the idea that "there used to be more women than men as programmers" just isn't true, at least as we understand the word "programmer" today, and the evidence it's based on has no bearing on why women aren't entering tech fields today.