I understand what you say but I really would love to see the statistics. For example, how many people played 0% house edge in December, how many bets were placed and in the end, how the balance between house and players looks like.
Btw if the statistics show that in the end, a net profit is 0, which means that players' bankroll in general, not individually, stayed the same when summarised, then Metawin's profit will be negative because it costs them money to run the website, run games, run servers, maintain a team of developers to maintain games and fix bugs or add/improve the code.
If running a business leads to negative financial result, it will be harmful for any business and it only can be accepted at begining or any short time during operation. In a long run, no business will accept it and they will have to make big changes for turning negative to positive or they will have to make vital decision to stop that product. Running it for a longer time without big changes that can turn the result from negative to positive, only harm their business more, so stopping it is a must.
If you see a product is available a long time, and there are many users with that product, likely it is profitable for the company.

Companies can't provably afford to operate at loss for long time and to survive their business either they fix those product cause them losses or just decide to eliminate it.
But there are products stays even if they are losing some funds, because it has a role like building an image on where they can use for marketing purposes. The main objective of that is to attract lots of gamblers which possibly play lots of games in their casino and with these their company can earn lots of profit with those players.
If its shows that game stay for long time that means they are doing good statistically and many gamblers still support it.