The reason why Brock is simple. 'Taker is from the good ole' days of wrestling, when men were men, marks were ignored, your legs got broken if you tried to be a smart mark around the boys before getting in the business, and women stayed where they belong - waiting to be picked up at the hotel bar. He came into this business around men like Stan Hansen, Bruiser Brody, and the like.
So knowing that, why would he drop the title to a skinny fat comic book geek, a guy whose only pushed as much because he's banging the bosses daughter, and a guy who's ass he almost had to kick back at Wrestlemania XIV because he still didn't want to job despite his back being in pieces.
He wanted to drop the streak to the last real man in wrestling - Brock Lesnar.