Why the twist.py will set the topic name as 'cmd'?

[JamieHuang28]

The published topic of twist.py have to be run with argument 'cmd:=cmd_vel/input/teleop'. I wonder why not set the topic published by twist.py as 'cmd_vel/input/teleop' directly?
At least in my usage, I do so.

Anyway, I appreciate your contribution, and I do simulation in my graduate thesis with your work instead of MATLAB.