You are focusing too much on making money with this. It's more to do with the ebb and flow of gaming trends and channel growth imo. Some people also stream games that have smaller communities. For instance when I was maxing out on a game I use to stream to 75 viewers tops. I was on top for months. This was the highest I ever saw it get to in one stream for this game in the entire 7 years I've seen it on twitch. With no chance of partnership, at least, got denied.
Another big problem is that someone could have 100+ viewers streaming a game for a month. Get denied partnership and then bam the games viewership dies to whatever reason.(usually the game dying). Then they have to start almost from scratch again.
The way the partnership program now is so unethical to me. Streams that get partnered are usually in the top 10% of millions of other people streaming content on twitch. That's millions of ad views that none of the streamers see a cent of.
Meanwhile you can go to youtube and are almost instantly partnered and can make income off your content. By doing this twitch gets to take all ad revenue and not spend a dime catering to streamers. Also a big chance that the unpaid streamer will bring other people who don't even know twitch onto the site. Creatings millions of more paying customers to twitch.
They only partnered people with crazy amounts of concurrent viewers. Well, because at that point if you aren't getting partnered you're probably leaving for bigger opportunities. By then you've probably worked on it 60+ hours a week for months getting there.
At least that's how I feel after streaming for almost 2 years and pouring my soul into it. As well as watching game streaming since 2008 or so. Don't get me wrong, I love the twitch community and have been involved since the beginning. I've seen people start from scratch to 50k viewers. But let's not forget twitch is a company, out to maximize profit. The community doesn't directly reflect a companies ethics. That's a rant, but you hit a sweet spot with your wordage.