It helps to have a forum that cannot be easily silenced.
Head-Fi, being unique in that aspect as they represent a large swath of the consumer base for a lot of these companies. Obviously not nearly all consumers, but the base, the enthusast with teeth.
What is (very) often the case, company hosted forums can be great until there is a problem, then dissent is easily silenced. Audio has a lot of places that are fairly well represented, and read, by the companies discussed. Independant forums, sometimes with a manufacturer subsection, sometimes not. Even so, the subsection is operated on independant servers, so their moderation is not nearly as strict as it would be.
Many companies have been very successful at having these kinds of forums taken down through legal actions and threats, however, the audio community, like any enthusast community, is just too great in size to even try such action, so it is best to work with their users, rather than silence them. Not posting in a thread, but knowing about it, is actually a very big step, the knowing about it part. The story ends up coming to an end when the issue is taken care of through the OP, word gets out and filters through, allowing for a kind of forum redemption of posts after the fact.
In this case, as well as others, audio enthusasts are lucky to have such places. It's not hard to have an independant forum, but it is hard to establish a community with as large of a swath of the market actively participating in discussion. Thankyou Head-Fi.