There are several definitions of sexism, one is essentially "taking someone's sex or gender into account when making a decision". This appears to be the definition the author is using by calling quotas "sexist". It's a very simple, easy to understand, easy to identify definition. It also means that in many cases (e.g. choosing who shoul speak at a tech conference), men can be the victims of sexism.
There's another definition, which is "actions that's designed to maintain & reinforce the institutionalised power structure among the sexes is sexist". Right now, if modern UK life was a video game, "male" would be an easier difficulty level than "female". It doesn't mean it's easy, just that it's easier. Many people, including this author did work hard. But there are statistically less problems for the "male" group. Sexist actions are actions that re-enforced that imbalance. This definition is harder for some people to accept because it means that you need to look at yourself and think about what power imbalances you might be benefiting from, and it means you can't just do s/female/male/g and make it just as sexist.
(There are some cases where there's an inbalance in favour of women, any men here ever took up knitting or crochet? Try getting involved in that, you'll see things from the other side)
There's another definition, which is "actions that's designed to maintain & reinforce the institutionalised power structure among the sexes is sexist". Right now, if modern UK life was a video game, "male" would be an easier difficulty level than "female". It doesn't mean it's easy, just that it's easier. Many people, including this author did work hard. But there are statistically less problems for the "male" group. Sexist actions are actions that re-enforced that imbalance. This definition is harder for some people to accept because it means that you need to look at yourself and think about what power imbalances you might be benefiting from, and it means you can't just do s/female/male/g and make it just as sexist.
(There are some cases where there's an inbalance in favour of women, any men here ever took up knitting or crochet? Try getting involved in that, you'll see things from the other side)