"Here, there are services that make life easier but not necessarily better, and that lose money every time they do business but exist thanks to their deep-pocketed investors."

It sounds like Prim did exactly what it was supposed to do: test the market. If there was indeed a strong enough market, they could work on creating a more efficient business without the need for outside capital. Investors are not in the business of throwing money away so people can get their laundry done, yet that seems to be exactly what the author is trying to say.

"Perhaps that money could be better spent helping people in need, and maybe so could the founders’ time."

Startups are incredibly capital efficient at testing needs. Even if there is nothing there, a lot of experience and knowledge is attained. Could such capital have been better allocated elsewhere? Probably not when you look at the potential upside.