it means not intended with the purpose to make money from it
founding doesn't always imply. a startup-like process of selling stock (or similar) to investors which in turn want some profit from it long term
it can also mean looking for donations to found a project, i.e. cover it's costs
but also not every non-commercial project ends like that, most do not
and even in case of OpenAI especially the larger donators could have sued, and had a decent chance of success. They just didn't (at least not until years later when the legal time frame to sue had been long passed).
naturally when you plan to make a large donation you should
- look at the exact used legal form
- if there are legally binding self imposed limitations
- if they are reasonably well formulated
- decide what you actually want from this donation, and when you think there was a breach of donation use-case binding (probably not the right English term)
- lastly vet the people in leading executive positions
in the end large donations are always a bit of an gamble, but what isn't