Are you sure you're attributing that advice to the right person?
Because it's orders of magnitude less valuable advice that "offer a paid version of the product". (Which you'll notice Patrick saying quite regularly about open source projects using charity as a business model.)
Selling software you've built is a proven way to make money. Selling consulting for software you've built is also a proven way to make money. But only one of those require you to actually do additional work in order to collect the money. The smart choice should be obvious to anyone with a fully formed sense of laziness.
The issue is: it's easier for a business, particularly the line manager, to just sign a contract for "support" which comes out of his OpEx budget than to get a company to deal with a charitable donation which will probably have to go through Finance and Legal.
Yes, the appeal to peoples' conscience by asking them to pretend it is a free trial unfortunately won't work at all to get money from businesses. On the other hand, a support package with a definitive price is much easier for a developer to justify to the boss.
If all you want is a web server? Nothing except support. If you use it as caching load balancer or media streaming solution, you get a lot of valuable features.
