Is wheat really bad for you or is this just a new diet craze?

Wheat can be bad. Monsanto is telling wheat farmers to spray the crop with round-up to kill it quickly for fast harvesting. Much of the wheat is contaminated as a result. Round-up is not as benign as they would like us to believe. Gluten also can cause an increase in intestinal permeability which can allow food proteins to leak out and promote various food sensitivities.
Too much is bad. Too much wheat is bad for everybody. There is also a small percentage of people that ate highly allergic to glutens and gliadins. These people must avoid all wheat. So yes, this is somewhat a fad.