I thought about this for a second (and restrained from pointing out how folks have pretty much learned to deal with Star Trek's "subspace radio" and how this isn't too far off from that) and posited that it might be due to some theoretical system akin to the Stargates' dialing program itself.
Namely, when you're on Planet Here and you're dialing up Planet There, There's gate's chevrons lock as you're plugging the address into the DHD; obviously, this is before a wormhole is established and yet there's still real-time interaction going on.
But this then got me to realize just how odd it is that the chevrons react like this. I mean, if I start plugging in a given address, it won't point to a particular gate until I put in the second to last chevron. Before that one, it could go anywhere (much like how if I were to rotary-dial a phone, there's no clear target until the last digit is dialed). As such, how could There's gate "know" that it's being dialed before the second to last chevron, since even Here's gate doesn't "know" that it's dialing There? If There's gate didn't start spinning and locking chevrons until between the 6th one dialed from Here, and did it between the 6th and 7th, I could understand. But from what I recall, of the times we've seen a gate with an incoming wormhole, it doesn't do it in a particularly hasty way.
It'd be very fun to imagine that every gate that matches the current combo spins and locks those chevrons, but I'm sure that would have led to far more planets out there realizing that the gate isn't just a weird object d'art.
PS: No fair quoting "If you're wondering how he eats and breathes and other science facts, then repeat to yourself, "It's just a show, I should really just relax"." to me.
PPS: The subject? It's the chorus of TMBG's song "Weep Day".
Simultaneous events don't happen,
We are isolated temporally.
And the part is never called the whole thing,
Although it bothers us to know it's so.
Every man is made of two opinions.
Every woman has a second half.
It's Samba Time for Tambo,
Weep Day for Urine Man.