How is that different than scratching one’s own itch?

Personal itches are more varied and strange than corporate itches. What companies are willing to pour time (money) into is constrained by market forces. The constraints on the efforts of independent hackers are different.

Both sets of constraints produce patterns and gaps. UX and documentation are commonly cited gaps for volunteer programming efforts, for example.

But I think it's true that corporate funding has its own gaps and other distinctive tendencies.

It is not, but the open-source community should be aware of this and not completely realign reorganize around the itches of specific stakeholders, at least the parts of the community who are not paid by those.