As it turns out, software foundations can be pretty useful. There's a tipping point in open source software when all of a sudden money becomes involved and it starts to get serious. Companies are formed, trademarks are violated and all of a sudden, stuff becomes real.
About 10 years ago I was around when Plone went from a small project to a "starting to get serious project". Alexander Limi and Alan Runyan had the foresight right there and then to realise that they needed a foundation, someone to hold the IP and trademarks of Plone. This got it away from being controlled by individuals or companies and instead placed in the community.
The Plone Foundation was formed in 2004 and one of the issues was that a company had been formed, Plone Solutions. in Norway to provide consulting. Having a company with the projects name in the title was a trademark violation. It also leads to confusion within the project and implies a relationship between the company and the project that doesn't exist. The foundation and the company talked and the company amicably changed its name to Jarn instead. Although Jarn is no longer around, Plone is still going strong and so is the Plone Foundation.
As another example, recently the Python Software Foundation had to fight for the Python trademark in Europe when a hosting company tried to trademark Python. The company backed down when the Python community stepped up to help the foundation fight that and proceed with its own trademark.
The Mozilla foundation, not the Mozilla corporation, holds the trademark and intellectual property for Mozilla projects. To commit to a Mozilla project, you have to agree to the committers agreement. Like other foundations it fights against people abusing trademarks. For example, taking Firefox, bundling it up with malware and then distributing it under the Firefox trademark.
In all these cases it's not a company holding trademarks and any intellectual property (depending on the foundation and the software license). Instead a foundation is created by the developers and maintained by the development community. It is the foundations job to act on behalf of the projects software community to maintain and improve it.
And I think Node.js is finding out why it needs one.