The majority of what you wrote is untrue. It does not stop 3rd party apps from writing to the SD card - period. Untrue. If the paid app you mentioned is not working properly you should contact the developer and insist they fix it. They are 100% capable of fixing it. This is not prevented by KitKat - it is only because the dev you gave money to doesn't care to support his product and paid users properly. Write a rant against them since that is where the blame belongs.
As far ranting again google providing a security fix that "no one asked for" - what kind of company would you want making your OS that would wait until they got barraged with requests to fix a security hole before acting on it? That is NOT how you deal with security issues - unless you want to end up in the position Target recently got itself and its customers into. Google had a responsibility to fix it before it blew up it its customers faces.
And then you go on to mention vague sourceless "stories" also known as myths, baseless rumors, and sometimes outright lies about horrible things KitKat has done to imaginary phones. Again, proving my point.
Now I don't care if you or anyone does or doesn't load KitKat on their phone and if someone likes the operation of JellyBean better then they can do what they want with their phone. There are differences between the two and some people like KitKat better and some like Jellybean better. There are absolutely not the dire consequences you and others are ranting about if you upgrade to KitKat. Like I said, and like you unwittingly proved, again I reiterate - the majority of information about Kit Kat and SD Cards being spread around is not true. It doesn't help your cause to spread misinformation. Also, you injected this whole discussion in a thread that was not about whether to upgrade and there are several threads dedicated to that already on here.