The triple crown is a hitting award, it's all about hitting the ball (average) hitting it far (home runs) and driving in base runners (RBI's)
It leans on the oldest stat in the game (batting average), the most glamorous (Home Runs Hello Babe Ruth!) and an odd stat invented by the early 20th century stat legend Ernest Lanigan (RBI)
And people wonder why they don't account for WAR when voting.
Probably the same reason they didn't use Total Average in 1982.
Personally I'm hoping for a repeat of the 1979 NL award