Do you at least have any supporting arguments on why there dumb?
Cause just stating they are dumb isn't helpful in swaying me ether way.
So maybe I'll think there dumb to if you after I read your reasoning.
Yes I do.
1) Relatively expensive (compared to traditional tents or sleeping under a topper)
2) Dependent on a flat spot the size of a vehicle where a vehicle can go
3) Garbage in the wind, you'll be rocking all night up there
4) Peeing in the night is now a chore
5) Can't add a heat source
6) You can't really cook and eat up there
7) They look stupid
8) They degrade your gas mileage, therefore more cost, and noisy while driving
9) More prone to theft (maybe a pro, someone would be doing you a favor)
10) Setting up isn't any faster than throwing a pad and bag down under a topper; if it is you're packing wrong
11) They aren't versatile like a Cimarron or Redcliff might be; can't take a roof tent on a river float, can't take it into the backcountry, can't fly with it, have to always take your truck
12) They occupy space that is more useful for a roof rack
13) More prone to mechanical failure and personal injury
14) PITA to mount/un-mount if the vehicle is your daily
15) Most are made in China of Chinese materials; some are made in USA of Chinese materials; very few outliers
16) I know I already listed it but it's worth repeating: they look dumb up there