Earlier quoted context omitted.
If you are unable to find out that 90 percent of people can't use a major feature that you thought would differentiate your product, you are missing all forms of feedback, including much more important sources besides analytics.
> if you are unable to find out that 90 percent of people can't use a major feature How would the users know they can't use a feature they don't know it exists? Let's say you add a brilliant new feature X, but due to a bug the users can't load the code for that feature so they never see it. How would they know to submit a form feedback for a feature they don't know it's there?
I'm getting the impression that people are just ignoring all advice about communicating with customers in their startups and just throwing stuff out there to see what sticks. Besides being wasteful in doing stuff no one wants anyway, what if that bad feature crippled your product and your paying customers have permanently switched to a competitor the instant your change frustrated them? And now you're bankrupt and can't afford analytics. Relying on analytics as a crutch to catch these things was the mistake in the first place.
Fun story I actually had forgotten about till now: I briefly worked at a tiny startup out of my school in the ending days of the internet bubble, trying to sell a "data mining" software product. Way too soon before it was cool, sadly. It was really hard to make the case that people needed to pay us $100k for the benefits we could get from their data. And companies certainly weren't going to go for a pitch like "if you launch a broken product we will catch that fact". They spend a lot of money to be sure that doesn't happen already. We even had one major customer figure out that they could just have an engineer perform a simple counter over incoming communications that would catch all they needed to know, and hence they didn't need our product anymore. That was kind of the end for us, in fact.