I think one of the issues with the term "low carb," is low carb in comparison to what?
If you use the govt's recommendations to get 60% of your calories from carbs, then I'd guess there are a substantial number of Paleo and Primal people who are low carb. And I think/hope that those govt guidelines have finally been debunked by the 30+ years that have made a lot of us who followed them look like fattened up cattle ready for slaughter. At 60%, for an 1800 calorie per day intake, the govt recommends getting 1080 calories from grains, beans, potatoes, etc. That's 270 grams of carbs.
If you use Mark's guidelines, I'm guessing fewer of us are "low carb." Mark talks about insidious weight gain at about 150 gms of carbs or 600 calories. Also, Mark's carb curve (which I know a lot of people don't like) doesn't address caloric input per day. At least the graphic doesn't; I'd have to search the blog post to see if that addressed it.
For a person whose point of reference started with cereal every morning, lowfat foods that were made to taste better by adding sugar to them, a lunch between two pieces of bread, frequent pizza (most popular food in the US), lots of fruit (because heaven knows you shouldn't get your vitaminC from peppers or liver), and crackers, chips, etc., laden with corn and HFCS, Primal and Paleo have literally turned their world and their pyramid upside down.
Anyway, I'm drifting off point. To discuss low carb, you have to have a reference point. Paleo and Primal are lower carb than CW. Within Paleo and Primal are subgroups that are at various levels of carb intake based on their weight, health, activity, and experience.
Until we define "lower than what," we can't really discuss low carb.
"Right is right, even if no one is doing it; wrong is wrong, even if everyone is doing it." - St. Augustine