"Why would an exhortation to stay on topic warrant thread lock?"
Uh... because I don't like you?
OK, seriously.
It doesn't warrant a thread lock. Simple as that, because it's a valid question.
That said, I don't come down on drifting threads generally because I tend to be more favorably inclined towards... free range... threads.
Yes, threads that drift can be frustrating, I agree, but the entire nature of this forum is more free range than the forum that spawned it. It was designed to be that way, and I more or less favor that concept, both generally, and specifically.
Some threads will naturally maintain tighter focus, while others will spread as they may.
As long as they don't spiral into a grand pissing match I'm inclined to let them go.
I do, however, exercise the right to shut down threads that have ceased to present new information and are now just a "yes it is/no it isn't" back and forth.
I don't know how the other moderators/admins feel about that, but I'd have to say they're more along those lines, too, as no one is herding posters back towards a central point...
