They have more salespeople, more relationships, more reliability. Pressure on original business. As Cisco moves into future markets, upstart companies are eating away at its original business. Juniper Networks, for instance, sells a superior router. Lack of familiarity.
Cisco has no brand name recognition and no distribution in the consumer space.
Intel and 3Com want the home-networking market too, and they do have name recognition and distribution. Don't get me wrong. I expect Cisco will find a way to remove these obstacles. And really, the only thing missing is a good catch-phrase like Wintel that will provide some household cachet. Help me out here.