Hi
There are many reasons for this, which 1 has been mentioned.
The domain in question is clearly a parked domain but the owner details will still be traceable.
We have a particular client who owns hundreds of domain names, but primary only use their main domain, with some been used for Seo, but not all because the ranking falls if too many used.
The reason why they own so many is brand protection, and over 80% are parked domains, and this just covers Europe, they have domains registered world wide through our company
Many thanks
John