I want to start by saying I generally agree with the theme of the article that the average American already gets enough protein without needing to specifically target it in fast food. However, I think this is not entirely accurate:

Overall recommendations have consistently hovered between 50-70 grams [of protein] per day, depending on weight.

That sounds low to me. I've seen nutritionist recommended minimums in the 50-70 range depending on weight, height, gender, and age, but recommended targets are higher. Especially for older men who are at higher risk of muscle loss with age, these recommended targets can be above 90 grams.

Edit: Getting several down votes, so let's add some sources.

0.8g per kg of weight, which comes out to about 55g per day for a 150 lb person, is a minimum, not an average: https://doi.org/10.3945/an.116.013821

Aging men may need to consume as much as 2g per kg of weight, which comes out to about 135g for a 150 lb man: https://doi.org/10.3390/nu10030360