The 100% tax won't be permanent, and chucking in money alone isn't going to save a game. New features and strengthening a community is what saves a game. The dev team is now doing a better job with the former, but could do a better job with facilitating the latter.

Also, Dcity apparently printed about 1.6 million cards. That is a lot, but not nearly as much as many other NFT games (e.g. Splinterlands). For sure, we cannot call is a scam, because the gameplay is real and the team has been VERY honest about their intentions and plans.