While I disagree with the poster you responded to, IME it's pretty common at small airports to even start boarding early. A number of times I've shown up before boarding time and they're already on Group 2.

It's just a different world than the large or medium size airports. I fly into them a lot and find it to be quite pleasant, unless you get delayed and the only amenity is a generic coffee cart with bags of chips.

Doesn't change the fact that the GA screwed up, but it's not because of early boarding.