I encourage anyone who feels they're not getting what they want from a mod to join a team and work on their own release. Once you're on the other side of the wall and providing content to end users, you will get a taste of how much they appreciate your work.

I've been on a couple of mod teams, and no matter what you do there will be people who disapprove. Ultimately, you have to have to be able to decide when good enough is good enough (because you will never be able to prove that it's "right"), and move on, or else you will be responding to requests until the end of time.
I only wish that there was a way to edit the physics for local offline use so that people so inclined could tweak things to suit themselves and not harangue the developers to change the data for everyone else (who may feel differently).
I have to add to this and say Yes! Try it yourself. Modding I mean.
I've also been in now 3 groups.
Two in the rFactor1 days that both tried to stay together but failed during the early rF2 days when the format was a BETA for the want of a another word. Not that I can't think of one that wouldn't be censored out anyway. But both have gone by the wayside.
The third and last had high hopes and good intentions to do things with rF2 but over the few years I worked on stuff for them it wasn't focused on anything. The words hit and miss, Willy, nilly come to mind. With no real goal for a team to achieve it didn't really achieve that much. Well not of note anyway.
I'm not a fan of one off's. Though ISI set the depressant for this form of mods.
And not a big fan of open wheel cars or those that were racing when my Grandparents were on their first date either! Though it seams most that post here and/or use rF2 are.
Enduracers have manage to at least to stay together and spend the past years trying to produce a "Multi car" mod for all of us. rF2 isn't multi car or series friendly, though a bit better now it's still not the greatest. But out of all the newest titles, What is?
I'm a artist, Painter, Textures guy. Physics are over my head and I wont pretend to be anything else but what I do know and understand is it's not easy. Producing good physics is hard, Producing great physics is (going from the comments here) impossible! Doing physics for a multi car mod were all the cars are different but competitive......
No matter who you are or what you think, others will disagree. No matter how hard you work on something you will get those that don't appreciate it for what it is. Not what "they" wanted or expected it to be.
You soon learn fast when your in a mod team to grow a thick skin and take the crap some dis out. But in saying that I can be, and have been abused for giving negative feedback on mods. Though not really on physics because I've never driven a real race car. Never driven a car on a race track. Never driven a car at 100% of it's ability and I really doubt many here can say any different. I'm more on the 3D and art work. In-game look.
Otherwise what is feedback? I learn from it. My harshest critic is myself. I'd suggest other to do the same.
We all have our opinions on things. Good, bad or indifferent don't stop saying what you think. No feedback is useless. All just good feedback is worse. We learn and build on the negatives!
If your not in the mod team, Don't get involve in a grudge match with a person that has a differing opinion to you! Allow the team to respond and discuss it with that person. It's their work after all and you never know, they may even agree with it!
We all could be so lucky to work with a team that has stuck it out for so long and had a end goal along with it.