Development must be funded somehow! We all must agree with that, but we also must agree that introducing a "tax" will open the doors to an attack vector.
Lending/borrowing is a HUGE $$$ business, it will also add another use case for BCH, using it as a collateral for borrowing/lending.
I propose creating a descentralized collateral based lending/borrowing platform and a stable descentralized coin pretty much like DAI.
Lenders can lend their stable coins to borrowers via a smart contract. Lenders will charge an APR% in expect for a profit. In the case of the borrowers, they will need to put BCH as the collateral asset to get 50% the worth of their coins in stable coin.
A fee must be charged either on the lenders or on the borrowers to fund development in bitcoin cash.
In example.
If the lenders decide to lend their money with a 10% APR (via free market). They will be charged a 12.5% fee within that APR.
or
If the borrowers decide to borrow stable coins from lenders at a 10% APR, they will be charge on top of that 12.5% of the whole APR profit.
It is not clear who would need to pay the fee. The borrower or the lender.
The beauty of this model is that nobody is forcing a TAX. Consensus and protocol change are not required either. The lenders or the borrowers will pay the development fee because:
1. They are using a financial service in exchange for a profit OR to get leverage.
2. That's it, do you need more reasons?
Of course, the management of the funds will also have to be managed in a descentralized, transparent and democratic way.
But the integrity of the Bitcoin Cash network will remain intact, which is the most important.