I don't see how, in the overall scheme of things, Gibson could qualify as being one of the 15 most hated companies in the US. They may be a big dog in high-end guitar land, but that's essentially a niche market. Not one person out of a thousand will purchase a new Gibson guitar in the next year. When viewed in terms of number of employees, number of customers, and overall effect on the economy, they're small potatoes. I'd say their inclusion on this list probably reflects someone's personal bias more than any consideration of objective criteria.

I'm not saying the current incarnation of Gibson doesn't suck, only that they don't belong on the list even if they do suck. They're not a big enough company for their suckiness to have much in the way of national ramification. If they're hated, it's by a very small number of people.