How many companies in the Valley develop software with tests?

Hi, I just moved to "The Valley" from London to work for a startup. I am shocked that nobody in this company thinks that writing tests is a worth cause (or at least one that we can afford). I assumed that on this day on age the value of tests was a given. I am told by my peers that here in "The Valley" writing tests doesn't fly because the need to produce software fast and the ability to pivot within days. Is this REALLY the case?