It's all the newbies coming into the industry - the only names they can find with high "exacts" are trademark infringements, but they don't know - or care about - the difference, since the one "fact" they've learned is that names with high exacts are more valuable...
There's no solution, either - if you imagine a still-available name that 1,000 domainers have looked at and ignored despite its strong exact count because we all know it's an obvious TM, as the total number of people rushing into domaining grows, there will eventually be somebody with more greed and less common sense, or desire to learn, and bingo that's one more trademark infringement!