Yup. Reading their post, it appears they didn't want to play the contemporary adtech game because it felt scummy, so they became unprofitable and quit.
Publishers massively overvalue their inventory and don't understand how their million views are worth only buttons. Ad networks can't pay more because they don't get paid more from the advertisers. The key is that no one clicks on banners any more, so it really is a race to the bottom.
Carbon Ads has pretty solid CTR, ads perform, advertisers renew, etc. It's not all doom and gloom for online advertising when you respect users and work hard to combine quality advertisers and publishers.
CTR isn't the only KPI by which ads are sold. These days, publishers understand that ads still influence even if normal users don't actually click. When a purchase is preceded by an impression from my ad network, in some cases I can get credit for a portion of it.