Why do you say so? Software patents are rarely guarded? Or something else?

In some verticals, like advanced materials or medical devices (outside of consumer/wellness at least), patents are expected.

If you're in the US, look into relevant court cases[0][1][2]. The courts tend to hold that algorithms are not patentable - what is patentable would be an invented machine which uses a software algorithm as one of its components. But even then, the machine needs to have some other inventive, patentable physical component.

(This sort of thing tend to confuse people since, the US patent office doesn't check for patent validity before granting patents. So there are a lot of companies that own invalid patents which have simply never been challenged in court.)

If you live elsewhere you should look into the laws of your local jurisdiction, but many places have the same or similar legal doctrine.

[0]: https://en.wikipedia.org/wiki/Gottschalk_v._Benson

[1]: https://en.wikipedia.org/wiki/Parker_v._Flook

[2]: https://en.wikipedia.org/wiki/Software_patents_under_United_...