I would be surprised to hear about any SF-based, consumer-facing web start-up who didn't follow comments about them HN. Not to mention a company that is in the customer satisfaction industry.
2) I can imagine their reluctance to visit here after the tone of the prior discussions on this topic.
3) There is no centralized comment section for the web. Not Slashdot, not Reddit, not here. They asked for comments on their site, not "please talk about this somewhere on the web".
Minor point: they're not here. Tell them that in their comments. :)