Many a modern conflict could be averted with proper usage of ;)
I think the avatars are I used in this comic to make clear that the comments were being made by different people are fun, and I enjoyed making them, but there's a reason beyond that why they're in the comic instead of names.
Specifically, I didn't want to use any names actual people are, were, or might use in the future. I can put as many numbers at the end any given name as I want, you just know someone's going to be using it somewhere. Plus, given that that's the solution, all the names would be horrible messes of numbers and symbols anyway.
Granted, I suppose there are display names that don't have to be unique, so that really wouldn't matter...
...Okay, sure, but avatars ARE fun.