Ghosthouse, Grant Green died going on tour because he needed money, when his doctor told him not to go.
Grant spent much of 1978 in hospital and, against the advice of doctors, went back on the road to earn some money. While in New York to play an engagement at George Benson's Breezin' Lounge, Grant collapsed in his car of a heart attack in New York City on January 31, 1979. He was buried in Greenwood Cemetery in his hometown of St. Louis, Missouri, and was survived by six children. Since Green's demise, his reputation has grown and many compilations of both his earlier (post-bop/straight ahead and soul jazz) and later (funkier/dancefloor jazz) periods, exist.
They can say what they want to say about "Rappers" but they're taking care of business and making money.
I think your evaluation of Leon is "right on target". Now I'm going to pipe your link into the big rig, relax and listen.
Enjoy the music.