Under ISS takes action against publication of Cisco vulnerability talk you can find a description of how Cisco and ISS envision security: massive interference with the freedom of expression of a speaker at the Black-Hat conference. Okay, he was a former ISS employee and probably used information he shouldn't have published - but it's exactly this ridiculous secrecy that undermines security - because attackers will gain this knowledge sooner or later - if security vulnerabilities exist, they will be found sooner or later. If someone reports about it publicly, at least you can defend yourself and take countermeasures. If the publication is suppressed, the end user is ultimately the victim - who has no chance to protect themselves - and even in an emergency by switching to another router manufacturer.
Therefore, it is indeed the case: neither ISS nor Cisco make a good impression in the public eye. On the contrary, their censorship attempts are actually only another argument in future product decisions to decide against Cisco - because you can obviously not trust their security statements.