In some cases, yes. You've to realize that each country in the WTO picks which battles to fight and which one's to let go.

For example, when Novartis lost the case, in Indian supreme courts, to ban the production of Gleevec (a Cancer drug) by Indian generic makers, they could've taken the arbitration to the WTO. However, this would mean terrible PR for both Novartis and US. Instead, PhRMA (a trade group for big pharma) and Novartis decided to let this one lie.

However, the US did recently challenge India's decision to force LCR (local content requirement) in it's push to use more solar energy in the country. USA, which is one of the biggest exporters of solar panels to India, successfully fought this decision.

I feel, in the end, the WTO is like any other court where two big conglomerates go head-to-head. Each one does not want to piss off the other to a great extent. And settlements are preferred over outright fights.