In former times netsolutions was pitched and feathered for the implementation of dns resolver, which forwarded not existing dns entries to a search form. Now google tries to convince users to do this again. Googles intention is to get more information about you and to we’ll more ads on the searchpage.
From a security standpoint the “does not resolve” is a far more useful answer then the “here is what we found” answer of google.
Good alternative which keeps your privacy is open dns.