Default [Q] [HELP]TiBu can't write backups to SD card

Okay, I'm running a newly rooted SGH-I537—Firmware: 4.4.2—Baseband: NE3
I rooted it this morning no problem with @geohot's towelroot; worked wonderfully.
My next steps were to backup everything and start removing bloat. Unfortunately, I wasn't even able to get to the back s**t up step, naturally.
When trying to backup the files to the exSDcard, I am told that it is unwritable! Funny thing about that though? When I say f**k it and try the backup anyway, it works for a fraction of a second, stops, and says insufficient storage....but each time I've done this a file leaks through and backs up to the destination, wtf?
I have been scouring these and other android forums looking for a solution to the problem, to no avail.
There was one potential solution, linked here: http://forum.xda-developers.com/show...php?p=44370296
But, naturally, it didn't work. I mean, I copied to the platform.xml file to my computer, did the necessary edits, and when I tried to paste it back into etc/permissions it wouldn't. So I thought, "maybe I have to edit it from it's location", NOPE! That doesn't work either; won't let me save with modifications. Granted, this method was for a different phone, but then again, so was the root method I used.
Which brings up another point: if I'm rooted, and ES File Explorer has superuser access, why can't I edit a simple .xml file?!
I apologize if this post comes off a little irritated, but I f**king am!
Anyone who can help with this will have my sincere gratitude and advanced thanks.......or I'm taking my phone to the shooting range.

*Warning: Irate rant contained below!*
It's like the folks at Android were sitting around the conference room—brainstorming—when someone spoke up and said, "GUYS! I've got a great idea! For this next update, let's not actually improve things, but rather(!), let's make our platform LESS functional! The consumers will love it! And I've got just the thing! You know how you used to be able to write things to the SD card?! Uh uh uh, NOT ANYMORE! Now what we'll do is pick things out of this hat I have here, whatever comes out is the functionality the end user loses!" And everyone just nodded in agreement! *rage*Oh.My.F**king.God! Who are these people and why is their incompetence so unfathomably pervasive?!
It's not just Android, but EVERY major tech company! Windows 8: Great example! Live Messenger/Skype merger: Great example! Apple(I mean, that's why we're all here, right?): Great example!
I could go on, but that's not why I am here, that's why I am in college.
Thanks (in advance) again guys.