Why don't people come into the Steam ecosystem and continue to be active?

A good and rather difficult question. No one is professionally promoting Steem, instead there is a lot of conflicting information on the internet. In addition, many people do not understand what Steem is and how it functions. People are used to investing in cryptocurrency and waiting for a price jump to sell and make a profit. Most people don't realize that there are other ways to make money in the world of cryptocurrencies.

Why don't the number of people participating in the Steam ecosystem increase?

We lack DApps, the ecosystem needs to be developed. Small steps are now being taken in this direction. I hope we will see results in the future.

I have already voted for @moecki as a witness!

Thank you for that. Maintaining active witnesses is one of the best ways to successfully develop a blockchain.