@dk organized a discussion with Muneeb of Stacks, and Muneeb seemed very confident in the fact that it increased their security budget. Without the incentives of receiving a freshly printed coin, Muneeb's reasoning went, the miner participation would be far lower (using RSK, etc as examples).
tldr you can make more money and spend it to get people to do more things when you're printing your own money.
Obviously, I'm not saying it's good but people have incentive to do it, especially when the market has trouble comprehending that this stuff will be worthless eventually.