Because its good to have a backup client... Most people have more than excess space to keep a clean copy of a client. People might have other mods besides abyss, and there could be a situation where another mod might leave something behind. By having a backup client you can ensure you'll always be able to play, regardless of whether or not your mods are currently working. And also so you don't have to go through the trouble of completely deleting everything and cleaning the client yourself, you can just switch to the clean one.
I could keep over a thousand back up clients, yet I have none.
It's totally pointless to have, since the 4 gigs are pack files, movies, and other data that you never actually edit..
Unless you use the pack file editor, and I doubt anyone does these days.
Removing my mods:
Deleted ijl15.dll
renamed ijl15.dat
deleted dinput8.dll
Done. I left my data folder, my abyss.ini, everything else.
And I have a lot more besides abyss/CS.
Seriously, I get being lazy and not wanting to write your own patcher, but being too lazy to learn how to install/remove the patcher? This is just going too far.
Blade, next patcher, put in a system that asks questions.
Either algebraic problems, basic questions about modding, something that forces them to read the first post, or a mixture of all three.
"Water is to life as Crackshield is to... ?"
I'd even lend server time to such a project, if you want to pull questions and answers from a remote source.