My biggest concern is this kind of "push hard" mindset and behavior becomes normal for them even after they are a well established business. Even worse is if this behavior is encouraged for all startups; one size does not fit all and that's something shouldn't be forgotten.
I worked at Intel for a few years, "push hard" was the norm and it was ruthless - they couldn't care less about my physical or psychological well-being. That was the worst work environment I've ever worked in. I was virtually at war with my colleagues every step of the way and no matter how hard I worked or outperformed my peers, it was never enough. Terrible way to run a company.