Wasn't it because of one crash, but five crashes in five years?
And also they figured their competition is Airlines, unlike the regionals whom use Air. (Air Wisconsin, Comair, Air Midwest, AirTran, Air Bob, Air defunct).
Many larger carriers use Airways and Airlines (United Airlines, South African Airways, British Airways).
It's all about the power and the marketing. And didn't they also at that time come out with their new paint scheme?