Well... it's not like I'm not often sorely tempted to go into other people's mods and re-balance them so that their game-balance doesn't suck. But I don't, for three reasons:
1. A mod is a work of art. I wouldn't re-interpret another person's art without their specific permission, unless they said very specifically that they didn't care whether other people used their work. I know how much work it takes to make a mod- I've done plenty of them
And I'd be pretty peeved if somebody treated my work with disrespect, so I'm very wary about the idea of going around "fixing" other people's work.
2. Most fans of the mod would probably not like it if I put my biases into a mod whose gameplay they like already, even if that gameplay has horrible, obvious flaws in terms of game balance.
Every game designer, even very good ones, has biases that influence their games. For example, I am very heavily biased towards skill-based play- iow, players of my games who aren't very good at flying and fighting (which are, let's be real here, the main activities of FL)... generally find my mods too hard, even though I go out of my way to make sure that the AI doesn't get any unfair advantages. For the Toolkit Mod, I've been very gently tuning everything to provide appropriate levels of challenge- "appropriate" ranging from "very easy even for people who've just started playing FL" for the first Mission to "wow, that's really hard even though the AI isn't cheating" for the last ones.
Some game designers are big fans of "gadgets" that alter gameplay (Epsilon springs to mind). Some are concerned with creating a gameworld that feels very internally-consistant (Free Worlds and TIE Universe are probably the best examples) and some game designers like secrets, hidden things, and little jokes (Monkey Universe springs to mind).
I've helped various mod developers with their game balance, and written reviews of various major mods, but in the end... everybody likes different things. There is no standard of "good" in gameplay, at the high end of design- which is why games as diverse as Unreal Tournament and Counter Strike, which are both First Person Shooters where human-shaped 3D avatars attempt to score points by killing each other with various weapons and accomplishing various objectives... can be considered to be "good" games. Or not. It's really just a matter of taste, in the end.
That said... game balance is much more of a science. All computer games can, at the end of the day, be broken down mathematically. Math doesn't substitute for reasoning, but it does supplement it, and it can quickly show a designer where a given area of a design is badly flawed.
It's pretty obvious that a multiplayer game about flying around in spacecraft and blowing each other and AI-controlled spacecraft is broken... when everybody who's serious and competitive flies the same ship and uses the same weapons mix, for example. "Vanilla" Freelancer is not
quite that broken in MP, but it's close. Solving those sorts of problems is pretty difficult, but it can be done, and many mods have come up with a variety of solutions that work pretty well.
3. Last but not least... a big mod like WTS... is tens of thousands of lines of code. Ok, so it's INI code, not something really complicated, but it's still one heck of a lot of code to go through.
And, when it comes down to it.... there are very few people who know enough about the art and science of game design to fix broken mods properly... and they do not (unfortunately, in my case) have unlimited free time. We all work for free here