The contract between Verisign and ICANN clearly states that there must be TOTAL separation (even phsycal) between the portion of Verisign which is the .com/.net registry operator, and other portions of Verisign, such as the Verisign registrar.
This move clearly broke that division since Verisign porudly told Wall Street that this move would boost profits for Verisign's operations.
Verisign operates the root servers on behalf of ICANN.
ICANN should have slapped Verisign with an injunction within 24 hours. It took ICANN days to issue a mild statement politely asking Verisign to remove the wildcard.
It is ICANN which failed in its responsability to ensure proper functioning of the internet. The DNS system for .com and .net is broken.
Verisign may claim that some other tlds also have wildcards. However, those are sponsored tlds (such as .museum) whereas .com and .net are general TLDs which do not belong to Verisign. Verisign has no rights to the .COM and .NET TLDs, they merely are getting paid to operate the servers.