Any and I mean any statistic someone throws at me I will try and dig in. And if I'm able to, I will usually find that something is very wrong somewhere. As in, the underlying data is usually just wrong, invalidating the whole thing or the data is reasonably sound but the person doing the analysis is making incorrect assumptions about parts of the data and then drawing incorrect conclusions.
Can't tell you how many times I've seen product managers making decisions based on a few hundred analytics events, trying to glean insight where there is none.
I think 1) holds (as my experience matches your cynicism :), but I have a feeling that data minded people tend to overestimate the importance of 2)...
In many experience, many of the statistics these people use doesn't matter in the success of a business --- they are vanity metrics. But people use statistics, and especially the wrong statistics, to pass their agenda. Regardless, it's important to fix the statistics.
What also can help for entrepreneurship is having a bias for action. So even if your insights are wrong, if you act and keep acting you will keep acting then you will partially shape reality to your will and bend to its will.
So there are certain forces where you can compensate for your lack of rigor.
The best companies have both of those things by their side.
What are you optimizing all that code for, it works doesnt it? Dont let perfect be the enemy of good. If it works 80% thats enough, just push it. What is technical debt?
There are often more errors. Sometimes the actual results are wildly different in reality to what a model expects .. but the data treatment has been bug hunted until it does what was expected .. and then attention fades away.
I bet you do this only 75% of the time.