The rangers frequently took part in community service and would never do drugs in any form. While this is respectable, it doesn't make for very compelling TV.
Pilot is much more talk than action - did producers really believe that audiences pay to watch action stars, even one with Norris's appeal, develop as sensitive characters?
If the purpose of drama is to provoke terror and pity in order to relieve those emotions in the audience, then Walker provided the ultimate catharsis for our band of fragile male egos.