I too would prefer to see conventions to be held when families can attend, but sometimes it's a matter of the greater good for the greater numbers.
I would say that if we could limit this to every third, or second, year at most, then families could attend most conventions. It certainly is nice to go to the Appalachians in the Springtime, or to the hot states in the fall, and New England in the Fall.
It certainly would be very hot in OK any time during June - August. Some hikers would be overcome by the heat, creating possible medical emergencies that we should avoid.
We also must think of the folks who are educators, who like the kids can't come during the school year.
Lets let the Board and the convention organizers use their best judgement. I'm sure they share your position.