I think a more apt analogy would be if you buy me a "free beer" and I drink it, then you're upset because I didn't buy you a "free beer" in exchange. If the beer wasn't meant to be free, then don't license it as "free beer".

The specific claim was not that pfSense merely used the technology, but also that they were hostile to a variety of community projects, including OpenBSD itself.

If I buy you a free beer, you are not obliged to say 'Thank you'.

Choosing not to do so may still shine a light on your character.

> ... a "free beer" ...

As in "one beer"? More like the mythical free beer river.

Anyway, your point still stand. It may not be a "moral thing to do", yet one could appreciate others not to pee in the mythical free beer river.