I think this part of the article the original poster linked to, explains it:
"There just ain’t any money in CB radios any more. How can Icom make and sell an IC718 for US$550.00? Yup, priced one off the shelf in Singapore last week. There is way more radio in a 718 than any CB out there today. 4 times as big, 4 times as much power, 10 times the components and complexity, and only twice the price."
Real ham rigs are just waaay better than export radios for just a little more money. For $300, there are a whole host of used ham radios that are available that are far and away superior to even a new export radio for the same money. Peruse qrz.com, qth.com, even fleabay, and you will see nice Icom 725's, 728's, 735's, Yaesu 757's, 840's (if you're lucky), Kenwood TS-140's, and so on, for $300 or less. Even a 20+ year old ham rig is light years ahead of a new export radio, and the word is getting out.
It seems the FCC has been largely successful in moving the serious CB SSB ops away from 11m and over to 10m. Once on 10m, they rub elbows with hams who educate them about the "real" radios that are out there.
I still dabble in exports because they are cool little toys, and because I already have several good ham rigs.
That's my theory.