Your logic is really interesting, OP.
OP: one woman dropped out of infantry training so that proves women aren't suitable
MN: but majority of male recruits drop out too
OP: but if majority of male recruits drop out too that proves women aren't suitable
fyi I have seen women in most of the jobs you mention (including fishing)
yes, numbers are small, but don't you think it might just take more determination to take on a job where everybody keeps telling you you're not really suited and you know any failure on your part will be proving somebody's sexist point?
fyi I used to work on building sites, not as a builder but as a digging archaeologist which is also a physically arduous job; most of my workmates were ex-builders, ex-roofers etc.
I met plenty of men who were incompetent or lazy or for some reason didn't pull their weight; nobody ever said "oh, that proves men are shit at the job"
The female workers otoh had to remember that if they didn't pull their weight, it would reflect on all the women.
For the record, that was never said of me: I was bloody good at swinging a pickaxe and pushing a wheelbarrow up slopes in those days. The job was no less hard than the work done by the builders on the same site, but the reason I felt comfortable doing it was that there was, at least, a little more acceptance of women in the workforce. I was averagely good, good enough to earn my keep; but to do a job in a very male-dominated industry I would have had to be outstanding.