I haven't personally paid thousands of dollars to use KNCMiner, either. I was smart enough to purchase BTC directly and only invest what I EXPECTED to lose in a mining operation for the enjoyment of participation. This thread should be renamed "Angry about your choice of investment? Blame others here!"
And if people are angry because they've got their miners, they are hashing away, but won't make positive ROI because of increased difficulty, that is perfectly fair.
If KNC have simply failed to deliver what they promised to, it isn't.