Is such a low cargo carrying capacity possible?

While yours was a misprint I have definitely seen many TT's that have very, very low CCC. You have to be aware when you are shopping. We found many trailers we loved - storage cabinets galore! Then did the math and realized that it was practically overloaded when accounting for wet weight and options...

No good having a bazillion cabinets if I can't even carry 3 cans of soup before I'm overweight LOL.