Accept the offer, rake in the cash, move on.
Whether or not the company eventually becomes a success does not affect the money you have raked in.
Be greedy, the investors are. If you're an engineer, you're the needed fuel they need for their fire.
> Accept the offer, rake in the cash, move on.
The closing part of this video sums it up perhaps: https://youtu.be/u6XAPnuFjJc?t=524
It’s for a fairly old talk called “Drive: The surprising truth about what motivates us”. In short, for work requiring cognitive skills, best performers don’t really get motivated by financial incentives (unless they have money troubles). Watch from the beginning for all that background and references.
FWIW I share OP’s feelings. I get really easily demotivated, I can’t bring myself to work on something uninteresting, let alone something I have a bad feeling about.
I am advocating it [this strategy] in this instance. It's not like this is weapons/defence, private prisons, tracking or mining.
It's a blockchain startup.