I actually enjoy this kind of work. Wonder if they're hiring.
I would argue that anyone would accept unpaid volunteer work from the best minds in a given field. Starting from that assumption and working backwards is how I arrive at the original assertion.
The "almost" part is aimed primarily at regulatory limitations where volunteer work is forbidden by law.
Both parties must actively want the other's offerings for work to make sense. If they say they are not hiring, there's no point checking any further whether this may be the case.