Because that leads to accusations of favoritism and bribery, and not just from ignorant players. Last time I tried that I had TiC accusing me of DRM both on twitter and every time the game launched, and putting code in TiC accordingly.
Let me make myself clear:
I am always going to listen to suggestions for balance or otherwise. I am by
no means required to implement them. And to say "well then, screw you, I'll just code it myself/find someone who will" is not only a blatant threat but a clear demonstration of entitlement.
Also, any claims that the proposed addon is not damaging to RC or only applies when GT is installed are fruitless. Not only is the first simply false, but but the second is only minimally true. As soon as an addon of that nature is developed, you will have people
clamoring for it to be usable even without GT. You should be well aware of how many people demand the Extractor be nerfed to 2x because they are completely unaware of the relative difficulty to the pulverizer and similar devices. Even keybounce, who is now reasonably well-acquainted with RC and is not the moron some others are, has made that claim before they used it. Additionally, it will lead to many cases of other hostile addons being developed, under the logic "well, that other one already exists". It will also lead to a flood of plugins designed to break what I have implemented to prevent things from being restricted to donators. This is where I completely lose control over everything I have designed and might as well give up entirely. I am not going to spend nearly 100% of my free time designing mods like RC if some jackoff with money for buying recoding or a mod-recoding-tool can just stick his dick in whatever behavior he pleases.
Pick one.
Now, if you want the reasoning behind my "no modifications" rule, do a little searching; I have said it all over this and other forums.
Now, if for
singleplayer you want to make this addon for your own personal game, go ahead. (Easier would be to compile a custom RC version). But as soon as it gets distributed it becomes public and against the rules.