Excerpt: The man who is credited with inventing the 401(k) plan isn't very impressed with the latest twist on the 25-year-old retirement program. Roth 401(k) plans will let workers save part of their taxable wages so they won't owe any taxes when they withdraw the funds after retirement. But Ted Benna, who designed the first 401(k), doesn't 'consider it personally to be a very big deal (even though) it's going to get a lot of press.'