I’d like to see this argument framed the other way. Other projects should want to see Zcash funded via this mechanism so they can benefit either directly or indirectly from the funding. Other than the obvious downstream projects, the Zcash Foundation has funded initiatives that are not directly tied to Zcash https://www.zfnd.org/blog/q2-grant-winners/.
I think part of the issue is how the funding is perceived to be going to the ECC, mainly as they are the only ones directly asking for it. In my opinion it’d be nice if funding was further decentralised more inline with the Placeholder proposal where a “Growth” fund or some such could be explicitly purposed for funding entities outside of the ECC/Zcash Foundation.