You got it; they're duplicating screen features. The tradeoff of recreating it (incompletely) is that the configuration is much more straightforward.

I have really handy screen macros that split screens, set hardstatus window titles, and setup different workflows after autodetecting the kind of project the base directory contains, but it's all done through shell functions and `screen -X eval` `process` this and `register` that.

http://superuser.com/questions/94612/macros-in-gnu-screen

GNU screen is a more powerful tool, but at the cost of having to read through the documentation. I can forgive someone for wanting to skip that step.

(but you shouldn't; terminal multiplexers are good for your health)

Same thought here. And since he's using OS X, I wonder if he knows about terminal groups?