You're misrepresenting the article. It gives multiple, clear, specific examples of the "trap".
Buffett's mobile-home empire engages in typical predatory practices, taking advantage of ignorant poor people. For example:
But the closing documents he set before them
held a surprise: The promised 7 percent interest
rate was now 12.5 percent, with monthly payments
of $1,100, up from $700.
Gotta hand it to Warren, he's got great PR people working for him. He cultivates an image of a folksy, down-to-earth elder statesman. He advocates feel-good social policies such as having the rich pay more taxes. He claims he runs his companies for the long term. But when push comes to shove, he has no qualms about making money from the "little people".