I've been running an open source, libre project for closing in on 24 years now, and generating revenue from it for about 17 years. There's never been any "profit", but there has been revenue.
I regard profit as what's left of the revenue after you pay the people who work on the project and any expenses, which is the way most corporations and accountants would view it.
The only sort of open source project that needs "profit" defined this way is one funded by a capital investment of some kind, where the investor expects a "return". While there are some open source projects that fit this description, the vast majority do not.
Also, as is typical for things linked from HN, this whole article seems very web-y and SaaS-y. There are other kinds of open source projects, believe it or not.