[uberman]

Bad data makes you confidently wrong. No data means you understand that your decisions are made based on your intuition. It is much better to know the risks than to be unaware of them.

[speakingmoistly]

To add to this, it's much harder to turn back while confidently wrong than it is when you know you are building on flimsy assumptions.

By the time you turn around on bad data, much more damage can be done.