I agree, but since sidechains generate "transactions" by nature, then some % of future revenue can go toward paying the investors.
Essentially, a FBA, like with stealth, where whenever there is a stealth transfer, onceuponatime's FBA gets paid. Whenever there would be a sidechain transaction, some of the fees would go to the miner, and the rest to the FBA.
I would invest in such a FBA.