Apparently, you are unfamiliar with the concept of inflation. If the supply of coins increases at a much faster rate than the demand for it, then the value of the coin will eventually decrease to somehow balance it. That's why a lot of high-quantity coins have a hard time organically increasing in value when there is no merchant support backing them either. The point of decentralized mining was always to give everyone an equal amount of opportunity to get coins while safeguarding the blockchain from malicious parties.

The generation rate of coins is not going to be increased just because a single miner can no longer monopolize the coins for himself. In fact, that you had been monopolizing it to a large extent for so long is a good reason to support the further increase of the hashrate.