> "in a business that is clearly managed by too ambitious people and will never succeed"
> "given that you are legally not a part of the potential fraud ring that you can't prove"
Consider:
1/ If it's a biz that's purposely mucking about without success...or a loss making entity for tax breaks: I have no problem in working here (Consider that I am in my 40s, used/abused in various "start-ups" and burnt-out. I need the money, and I'll take it.)
2/ If it's a company involved in criminal fraud: I'd run away as fast as my feet could take me. The problem with fraud is that eventually the authorities will catch up. If the owner is a criminal, he'll do anything to save his backside...even throwing innocent employees under the bus. You might be exonerated eventually. But that eventually might take years...decades.
If you suspect that it's fraud, you should seriously consider whether you want to be a part of it, even if you can't prove the fraud. Examples are companies centered around cryptocurrencies: not all of them end up being rugpulls, but enough of them do, making every new company potentially morally risky for each engineer.
If you only suspect that it's an overly ambitious project, but not fraud, the moral risk is obviously lower. Sure, it may be economically risky - as all unproven business models are - or you may discover the fraud later (like the author apparently did). Examples are startups like SpaceX in its initial stages: there was nothing ostensibly fraudulent in trying to make and sell better rockets, just very economically risky.
Obviously, the devil is in the details, but if you're honest with yourself, you should do your due diligence (i.e., does it seem like fraud or not) and determine your moral risk appetite. It's up to the wider society to reduce and punish the unacceptable levels of moral risk, regardless of the appetites of individual engineers.
Sure, 99.9% of startups may not get there but we saw in the past some wild unexpected successes. Plus things may change along the path as markets evolve and if they pivot successfully into new areas they may win the first mover situation, even if original mission won't ever be accomplished.
Then again, if it is doomed to fail from the start, it is unlikely that I would really enjoy working on it.
I was with a startup for almost a decade. During that time it had four different owners. At one point it was "clearly managed by too ambitious people and will never succeed", but the parent owner and remaining founder saw this and found a legit buyer.
When this happened, we were wholly owned by a major conservative company but operated independently; the fact that "adults" controlled the purse strings was what made the situation work out well in the end. (For me, that is. Other people who drank the kool-aide were given nice severance packages.)
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Thus, you really have to know the whole story: Who's the investor? Who has power? Who's controlling the purse strings? If the business has potential, the investors will fire "poker player" leadership in situations like this.