This isn’t quite correct, or at least it’s somewhat misleading. The total issuance of 21M coins remains unchanged, so it’s not really “creating a big pot of Zcash”. Also, the hope is that a distribution mechanism will be able to be agreed upon and implemented in relatively short order, so while there will be a temporary dip in the issuance curve until that’s done (and a bump once it is), overall the issuance curve remains the same.
I also want to note that the purpose of the block subsidy is largely to ensure economic security via rollback prevention. The question of how much the chain should be paying for security is highly relevant; we obviously don’t want to pay too little, and make 51% attacks feasible, but every coin that we overpay for security could instead be used to further the development of network infrastructure, education, and so forth. By further decentralizing how development funding is awarded, the hope is that we’ll be able to create greater competition for those resources and in doing so drive better outcomes for the ecosystem. I’m personally in favor of a system of retroactive grants funding where the community pays for results, instead of paying organizations, to replace the current system of grants (some embedded in the protocol rules, but they’re all grants) that pay in advance.