On first sight it is very appealing to fund infrastructure development from the coinbase. Just as miners provide a service to the community by keeping the timestamp server ticking, so do infrastructure developers by maintaining and developing the software. Why should miners be rewarded for their communtiy service but developers not? Let's say we would agree to distribute 8% of the coinbase to a specific address of a given dev team.
Now for miners there remains a well-defined relation between the effort they put and the reward they receive. They prove their work by finding blocks and receive 92% of the coinbase. More proof-of-work, more reward.
For infrastructure developer there's no such relation between the effort they put and the reward they receive. With every block found they receive 8% of the coinbase. More dev work or less, it doesn't matter. A feedback mechanism is missing.
While some incentives persists for the dev team (to deliver high-quality code due to valuation of their network token compared to competing network tokens), one incentive is lost: to compete for better development within the network itself. The dev team which achieves to redirect a share of the coinbase to their account has no incentive to share it with any other dev team, other than goodwill. The network is then at the mercy of this dev team.
Funding the infrastructure development from the coinbase might be the right thing to do if a proper governance model for the distribution of the available funds is implemented. And funding infrastructure does have very high priority! But its governance should be properly discussed and not implemented lightly or in a rush.
Without a well-discussed and communtiy-wide agreed-upon governance model for available funds such an implementation is an irrevocable power grab of the network by one dev team.
Effectively this turns the IFP debate in a debate on a multi-node vs a lead-node ecosystem. Which one do you prefer?
Governance > Finance