There are a few different reasons someone might want a software patent at a startup stage. Investors view Patents as an Asset, which can increase your value in their eyes. Legally, they can be leveraged (once granted) to protect a particularly novel idea and minimize competition. They can also be used defensively, protecting you from being sued. They can also be licensed, which means you could potentially generate income.

How much value they have, or if the system works properly is a different conversation entirely. My own personal stance, I'm interested in patents for defensive measures only. Meaning, if someone else tries to sue me over something I created (saying they created it), I have something on my side to protect me.