The reason is very simple. Much less girls play competitive games then males. And no, you cannot cite that one study that shows females make a substantial amount of gamers, because that study focused on all games, including very casual stuff.
As for so called misogyny in the gaming sphere, that's just bullshit. Just because someone uses a gender targeted insult towards you doesn't mean it's misogynistic. If anything, I'd say girls get very much preferential treatment when it comes to games, but I'm not gonna claim that's a fact, that's just my opinion based on anecdotal evidence.
The reason why tournaments that feature only woman get lesser prize pools is also simple, they don't have as wide of a reach when it comes to audience, so the sponsors make less money out of sponsoring them (yes, sponsors make money out of sponsoring - it's called marketing), it has nothing to do with being overlooked.
And the last thing - most females just aren't as good in competitive games, I'm sorry, but that's often a fact. On average man will for example have faster reaction times Source and that's just one factor.
So please, don't bring gender politics into this. It's just as simple as this:
TL:DR
Less women tend to play competitive games.
Women are worse in competitive games on average.
I share some of the views with you, and Im glad we have sparked an open-minded conversation.
I am by no means a misogynist, neither am I a feminist. I am way to busy with real world shit to police myself with who's offended by what, and the wage gap and so on.
But consider this, in our world, the esport route of making a living is still unchartered territory. Very few people (in the grand scheme of things) have made a success out of competitive gaming. Do you not think that what I said about the promotion of female esports is important, not only to even the playing field, but also to branch out? To bridge the gap between certain walks of life that wouldn't otherwise be exposed to this type of thing?
As I said in the post, I have my own views, some of which I did not share in the original for fear of causing a comment war.
But thanks for your reply, I really appreciate it!
No, I do not think the promotion of specifically female eSports is important. But nor do I think promotion of specifically male eSports is important. Also, there is no such thing is specifically male eSports for the most part. Any woman can go and train and become the best in any eSport and just compete in the "regular" leagues/tournaments. Many do and in games like for example Hearthstone they tend to do quite well. There it's again just a matter of how many females vs males are there in total and I would guess that the numbers probably represent the percentages of the genders pretty well.