It's all about reaching as many people as possible, which unfortunately caters to the casual fan and greatly ignores the hardcore audience. Sometimes you get lucky with a group like Dave Matthews Band, but for the most part, any and all mainstream bands are going to play the songs that got them to the main stage in the first place.
"One Step Closer" will always make the set, and we might never hear "With You" again. The only way around it, in my opinion, will be an LPU Tour. Even if LP lose their money and popularity tomorrow, they'd just be like all the other nu-metal bands (Limp Bizkit, anyone?) who play all the hits hoping to fill a barn in Russia with nostalgic fans.