I think what you describe is common, if not just part of the way everything works. So, not a blind spot, but also not something to dwell on. The in-determinant nature of forecasting - especially with respect to revenue/profit estimation - is almost moot when you're trying to determine if a nascent company is going to be able to make 200M a year in 7 years time. That's why you see so many of the factors for venture funding following well worn qualitative pathways: Tons of users, market size, stickiness, monetization capability, founder grit etc...
They are proxies for expectations based on past experience, given the glut of quantitative measures that aren't strongly correlated.
In the end, you're playing in the unicorn league if you think you are.
Maybe, but that circular logic doesn't help establish legitimacy. And if we can agree on that, then where does the investor industry's legitimacy lie? "We have the money, by various mechanisms, and everything else is a fairy tale?"
No, the concept of a "legitimate investor" is not a fairy tale. Unless that's what you're saying, that the entire VC industry is illegitimate, that it exists outside the world of dependable knowledge? Why would LPs give GPs money if that was the case? It seems to go against all financial sense.
They are proxies for expectations based on past experience, given the glut of quantitative measures that aren't strongly correlated.
In the end, you're playing in the unicorn league if you think you are.