I bet the reason they did this was because the term "class" is very misleading to ma and pa kettle from Arkansas.

At least twice I've overheard couples staring at their boarding pass and mumbling to each other, "Honey, where is the W-class section?"

If I'm in a social mood, I'll chime in and explain the difference. Once I had a nice old couple buy me a cookie from Starbucks for spending so much time with them, explaining their boarding pass. They were traveling to NYC to visit their daughter (whose husband was killed in WTC), so I had them upgraded with some soon-to-be expiring 500-milers.