There's probably a ton of stuff that Arlo and I disagree on, over the years, it could amount to a book the size of War & Peace.
However, we agree on the love and respect for the planes of World War I, World War II, and the men who flew them. And we agree on the love of both Aces High and Air Warrior. It's common ground, and he's my friend, whether we agree on much else, or not.
He's also a human.
So, yeah, I'm concerned by his absence. And I hope nothing bad has befallen him. If you can't have concern and compassion for a fellow enthusiast, maybe you should look in the mirror, the problem likely resides in who and what you see there.