Certainly some of the things the Koch brothers have done and donated to are worthy of admiration...and after the Citizen's United decision by the Supremes, both parties are in the pockets of big money.
But most of what the Koch's have done with their right wing libertarian agenda is not good, and not admirable...
read "Dark Money" by Mayer, for a good summary.
In particular, their efforts to perpetuate our fossil fuel based economy, from which most of their great wealth is based, in the face of overwhelming evidence of what emissions are doing to our environment is despicable.  I will apologize to my children and grandchildren for the world we are leaving them and for what people like the Koch's have done to prevent a course correction when we still had time....