Carbuerated bikes have to sit for a few minutes and warm up, let the metal of the engine expand so all the internal tolerances are right and the fuel/air mixture is where it needs to be. Fuel injected bikes don't need to sit to warm up, because the computer is adjusting the air/fuel mixture on the fly anyways. They still need to warm up to make sure everything's in the right place, but they warm up much faster if they're actually ridden. Even Harley Davidson switched over to fuel injection in like 2007. Import bikes started switching in the late 80's. So no bike newer than 2007 should ever be sitting in its driveway annoying the neighbors.

Go be friendly for a minute, ask the guy a little about his bike. Maybe he doesn't know this and you can teach him, saving him time every morning and allowing you to get more sleep. Most bikers just warm their bikes up because that's how it's always been and they've never thought about why they do it. If you're respectful, chances are good he'll try to work with you. Most bikers I've met have been very helpful people, we're just so used to getting hated on by people who don't ride that we act a little standoff-ish at first.