On the contrary, patents are one of the only things
besides engagement that may be valuable about a typical startup. The technology/software that powers any given startup is usually easy enough to replicate (excepting massive cutting-edge projects like SpaceX/Tesla).
Most companies would prefer to copy your features into their own product for ~$1M of engineering time over the course of a year or so (3-5 full-time guys assigned), rather than pay tens of millions for an outside version that would have to be integrated, and wait for an acquisition to go through (itself probably costing close to $1M just in professional fees).
Startups therefore only get bought if they have a userbase that the acquiring company may be interested in, or if they have a good patent portfolio/other interesting intellectual property. Patents are exclusive government-backed monopolies over systems, techniques, or processes ("inventions") that can be used to force competitors out of business (ideal but rare, because competitors usually have their own relevant patents that need to be licensed). More often, patents are useful leverage to get competitors to agree to a mutually-beneficial cross-licensing deal. Thus, a startup with 0 users may be a good buy if they have patent(s) relevant to the problem space.
Entrepreneurs should apply for patents because entrepreneurs need ammo. Big companies are not going to buy your company and transfer millions of dollars because they think you're a nice guy. There are a lot of nice guys out there, but there aren't a lot of guys with a patent that a big player needs. If you want to be taken seriously, you need to get some chips before you show up to the table!
Disclaimer: IHNIWITA (I Have No Idea What I'm Talking About). Not a lawyer or an investor.