I'd make a confident guess that the "basis" for this suit is a Supreme Court opinion from the 80s ("Hydrolevel") saying basically that standards-setting organizations can't allow themselves to become a tool for conspiratorial members who have an anti-competitive agenda.
VeriSign tried to make a case that ICANN's decision reflected a bias in the structure of the organization. That's really a question about the ICANN bureaucracy and the objectivity of the decision-making process. Obviously the judge approved of ICANN's actions. But I don't think that approval has anything to do with the actual merits of the decision, but rather the procedure used to reach it.
My personal belief is that ICANN is more benevolent than VeriSign, based on the fact that I've met two of the ICANN people. The crazy thing about the plaintiff's case is that, if anything, the ICANN folks are *too* rigorous about their consensus procedures. That is, it is more likely that the DNS will suffer from ICANN's inability to make command decisions than from its "domination" by any particular interest.
Most of the world would be very happy if US companies, or even companies only accepting transactions from the US, were moved out of
And then there is the fact that ICANN prefers to model the "law" it applies to the internet on US law. Where US law is superior (say, First Amendment) that's a good thing. But someone who lives in a country with real libel laws, or substantially different trademark laws, must be frustrated by this tendency.