A useful discussion, but an incomplete one.

Are the gluten haters correct that modern wheat varietals contain more gluten than past cultivars, making them more toxic? Unlikely, according to recent analysis by Donald D. Kasarda, a scientist with the United States Department of Agriculture. He analyzed records of protein content in wheat harvests going back nearly a century. It hasn’t changed.

The actual study is a lot less cut and dried:

Gluten fractionated from wheat flour by washing starch granules from a dough (sometimes called vital gluten) is often added to food products to achieve improved product characteristics. About 80% of the gluten used in the United States is imported—mainly from Australia, the European Union, Canada, and China. The question of how much vital gluten contributes to the total consumption of gluten (wheat flour and wheat grain and vital gluten) is complicated by a lack of accessible information about gluten production and imports for the United States in recent years and by indications that imports are rising rapidly. I make a crude estimate of what both factors might be as follows: Gluten imports were 177 × 106 lb (80 × 106 kg)(19) in 1997 and 386 × 106 lb (175 × 106 kg) in 2007.(20) A two-point linear extrapolation to 2012 indicates that imports would currently be 490 × 106 lb (222 × 106 kg). I assumed that the population of the United States is 330 × 106, that vital gluten is 75% protein, and that 80% of vital gluten is used for human food, to obtain a per person (per year) intake of gluten of 0.9 lb (408 g). Following the same approach, I estimate the gluten intake in 1977 to be 0.3 lb (136 g) per person. Thus, it appears that vital gluten consumption has tripled since 1977. This increase is of interest because it is in the time frame that fits with the predictions of an increase in celiac disease.

He also measured gluten content from historic harvests in Minnesota - while our grain imports have quadrupled in the past 40 years as China's exports have skyrocketed. Chinese wheat is largely grown for noodles, and Paul Roberts documents in The End of Food how the Chinese have been selectively breeding for greater and greater gluten content.

IF gluten (or some associated wheat ancillary, like FODMAPs is a non-irritant for most people, a mild irritant for some people and a severe irritant for few people

AND higher gluten-content wheat is being imported than historically

THEN a correlation between increased incidence of gluten-related sensitivities and gluten content is worthy of investigation.

Granted - the country is going batshit for gluten-free stuff right now. The response is overblown. Lots of people are trying to go gluten-free with no reason and, in many cases, no understanding what gluten even is. But my wife and my daughter both get eczema from wheat, and always have. Doesn't mean they don't eat a donut every now and then, but I can give my daughter a couple crackers and watch her scratch her hands within about three hours.