It's not a joke. rePOWCHA stops bots. If a bot automates sending the amount to get by the CAPTCHA, the bot won't be able to afford paying this amount at scale, because when you notice that the bot abused your service you'll flag it as "abuse" and won't refund the bot's deposit. Past some threshold of $x per CAPTCHA, bots can't afford to bypass them.

The reason spam is everywhere is that the cost of sending spam is low. The solution proposed by rePOWCHA is to increase the cost. It's a form of proof-of-work.