Trade mark rights can be incredibly valuable. But those rights need to be looked after. The owner has to use the trade mark, and do so properly. In most places, the legal rights have to be renewed every so often. And if a trade mark gets taken into the language as a descriptor, the owner may lose its rights if this breaks the connection in consumers’ minds that the trade mark indicates the product offerings of the owner.
Alphabet challenged a transaction transferring to new ownership a large portfolio of domain names that included the word “GOOGLE”. So the buyer responded by alleging in Arizona court action that the GOOGLE trade mark (in the US) had met with just this fate. The court disagreed and so did an appeal court in San Francisco today. It’s a risk but the proof is sometimes just not there.