I don't like how people change what someone spent months or years working on just so they can like it better. That's like approving of someone who gives the Mona Lisa a mustache because they think it'd be better with one.
Based off of this mentality, I assume you're against bodybuilding, exercise, hair transplants, boob jobs and other cosmetic surgery practices.
After all, nature and the universe worked so hard just to make you the shape you were born. Why lift weights or eat healthy? You're just messing up what the universe spent years to create.
I also assume you are against the construction of houses and other buildings that arguably make living conditions better for people. Again, the universe and nature worked millions of years to create all of the trees and nature just they way they are. Who cares if it's more convenient for people to re-arrange nature to build houses and live more comfortably? Building houses to keep people sheltered is EXACTLY like putting a mustache on Mona Lisa. /sarcasm
The bottom line though is why do you care what someone else chooses to do with their private copy of the game? Do you believe modding games is a sin that greatly upsets God? Just because you don't enjoy changing and experimenting what what has been handed to you, does that mean no one else should be able to? It's not like it affects your personal copy of the game.
Paying for mod tools would translate to paying for mods... which, in turn, would translate to pirating mods. It's a slippery slope in which few or no one wins. Either leave the game vanilla or allow mods to be donated to the community; which would mean having modders not have to pay for the tools.
Just my tuppence.
I believe it would be illegal to charge money for the mods we create, so I don't see that becoming an issue. Only Bioware has the rights to sell them.