I think most of the dislike towards Sennheiser is because they're acting with regard to supply and demand to maximize profits. Corporations tend to be morally neutral or amoral IMO, and that can come across as "evil" because evil is very much similar to indifference to human interaction or emotion.
In particular, consider living in the desert with an infinite water supply. You're the only one with the water supply, so taking supply & demand into account, you sell it for $10,000 per 16oz bottle. From the business perspective, this may be a very good decision since not many people are wandering around in the desert to begin with. I don't know anything about formal economics etc. but I think it's pretty easy to see intuitively why there's a tradeoff here between "playing nice" and "making money". Big companies don't play nice and they probably never will.
The thing is if you sold your water bottles for a good price in the example above, you may see less overall profit for a while, but begin a shift of the face of industry and economy itself (in the case of water you might even enable new towns etc. to be settled in the area where it would otherwise be impossible, thus leading to a massive increase in customers and resulting profits).
In the case of headphones, well... who knows what would happen if someone like Sennheiser chose to sell an HD700-like headphone for a really cheap price. I like to think optimistically and imagine that they'd gain massive popularity and adoration from the audiophile community, the mainstream, and as a result make bucketloads more money too. But I don't know anything about economics.