It’s taken me many years to learn that you’ll catch a lot more flies with honey than with vinegar. Some people just don’t care. But if they’re in a position where they need to care, then they had better put the vinegar away. Lol.
Basically need to tell them that you can’t browbeat people into voluntary work.
You summed it up in the quote, and in the line i cut and pasted from your original. Simple and direct, and better just written down in one short sentence in an e-mail and send it without any further discourse within it.
The shorter and more concise you make the statement, the harder its going to hit. And this person needs hit.
I feel your pain. My NPO has just a few of us that do some pretty hard labor efforts, including using saws, my skid steer and my Ag Tractor and bushog and my trucks and trailers, only to be snubbed by people that wont help, but will offer, "You know what you should do?" or "You could have made this better by doing that over there" (not knowing over there is not our property to do anything with) Lots of them want to claim they helped, or actually say they built it, when in fact they simply scheduled something else they preferred doing instead of being there for the work days.
Its not fun being out of town, and have an acquaintence point out another person at the same event, and relay they told them they had built all these things you had spent the last ten years building, looking at me like which one of you is lying about it? I pull out my phone and show them a two minute video, after calling that other guy overn to look as well......