He only goes crazy with the samples on music that is released independently or thru small labels that don't have to worry about sample issues. Nobody is out here trying to sue...Roc Mariano, so he doesn't have to worry about that when he gives them beats. However when he works with major labels it becomes a big issue. Remember, he had to give up 100% of his publishing on Break The Bank just to get it on Q's debut album. That's how expensive the clearance was. And two years ago on DAMN you best believe that sample on Fear was expensive too, but in that case Interscope clearly was giving Kendrick and company whatever they wanted (see: the three samples on that 9th Wonder track lol).
Same with Madlib. Most of his major releases have been on indie labels that never really deal with clearances. He had to deal with it on Bandana because they signed to RCA, hence why multiple songs were apparently cut from release.