I believe you misread this.
The "she" who said the store was protecting the customers' credit scores was the woman who worked at the store. The teacher who organized the field trip is male: Brian Page.
Here is a longer excerpt from the article.
Standing behind the counter, Tonya Webster addressed the assembled students. “Life happens,” she said. “It does. Try not to live beyond your means. If you do, we’re here to help.” She also made a pitch for the bargains behind the jewelry counter, wondering aloud why anyone would ever pay retail when they could just come there.
After 20 minutes or so, the students turned to leave. “So what are we going to protect?” she said to them as they walked out. “Your credit scores!” she shouted, answering her own question.
“I was taken aback by her honesty,” Mr. Page told the students who had stayed behind on the bus. “She said that this is where you go when you’re in trouble, and she worked there! Everything in there had been taken from somebody.”
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In any case, these students got to see some real life examples of astronomically high interested rates and consequences of living beyond one's means. Sounded like the students got a lot out of the experience.