The point is to not become as good as a smart nerd, because you'll be playing catch up your whole life. The point is that you need to show that you know enough about your idea on the technical side that you can communicate effectively with your partner. Knowing some basic principles of coding goes a long way in that regard, and it also shows that you are willing to become interested in things outside your level of expertise -- even if you aren't willing to become a master at them.

I've sat down with many people who needed a technical person to implement their idea. But as they were talking it should have became immediately clear to anyone with technical knowledge why their idea was flawed in fundamental ways. But these people never delved into that side, so they figured programmers could somehow perform miracles and make it work, and had unrealistic ideas of deadlines, money that would be needed, etc. As a programmer, you don't want to have to deal with correcting many false assumptions someone is making and any others they will make as you build the product, when there are plenty of "technical enough" entrepreneurs who know whats possible and whats not.