I have no issue with companies making billions without turning a profit. I have a problem with companies continuing to not turn a profit after amassing a billion+ in capital. If you can't find a way to make money after climbing up on that much capital, then you shouldn't be in business.
Yes. But what they consider valuable isn't always what (say) a small business owner would consider valuable. Small business owner is looking at profits, overhead, taxes, etc. Investors are more interested in whether users like the product/service, whether they stay around, etc. The idea being, that if people love the service, eventually you can find a way to monetize it. Facebook, for example, didn't make a profit until 2009 (I could be wrong), which is two years after they soaked up the migrants from Myspace, and five years after the company launched. Five years with no profit is absolutely insane if your business is selling burritos.