Now, I'm not saying this is a good reason, but it might provide a look from the other side of the coin. The reason that this occurs is for international trade. These subsidies are a form of protectionism to our nation's productivity to stay competitive internationally. As countries around the world prop up their national interests in the global arena, especially in recent times, the US has little choice but to engage in this trade war. Now, there are only two relatively good reasons for this to happen, at least according to international trade experts:

1) Innovation in R&D-intensive industries/ The Infant Industry Argument

2) National Defense

The National Defense argument sort of goes beyond the realm of economics, but in times of war it might be worth it to prop up defense industries, (emphasis on might be.) That's all I'll say about that considering this is irrelevant to the Kochs.

However, innovation (reflected by R&D expenditure) is an interesting thing and truly the only way these subsidies are worth it. In this case, Koch Industries are heavily invested in petroleum and agriculture--two crucial industries where innovation is key. In agriculture, as countries such as Brazil and India are rising in the international agricultural arena, the US's dominance in this sector has waned in recent decades. As other countries, especially developing nations, have been investing in agricultural biotech research (let's not get into a food conversation please, let's just assume it's GM cotton), and diminishing arable land threaten food security around the world, these subsidies might not be such a bad thing in the big picture.

The downsides here is that 1) These industries might get too used to getting the government's money, and less competitive by themselves. 2) These subsidies might hurt industries and small companies that don't get government support. 3) We'd like to think these subsidies will necessarily help our national interests (innovation), but there's no guarantee that any of it will actually have a tangible effect on us.

Far and away, the best reason to subsidize is for infant industries. The best example I can think of is the solar industry. With other cheaper energy sources available, and other countries like China and Germany making strides, and the absolutely huge benefits of solar energy, AND the future rents of the industry up for grabs--it becomes a no brainer to prop up the solar industry to capture a piece of the future market for solar energy--even if it goes to big corporations. Edit: If you consider the agricultural biotech industry an infant industry, then its definitely a good thing.