I do nott reject in toto what is termed existentialism. Some interesting thinkers have commented on existentialist themes with which I agree.
I do reject Sartre as being a serious thinker. He was IMO a weak-minded populist who extended his Warholian 15 minutes of fame for a couple of decades when crazy shit like Alan Ginsberg, rolfing, EST, and Maharishi Mahesh Yogi were taken seriously. A period of especially slack-minded mass culture unlike today's more mature culture of the Kardashians, hip hop, and Family Guy.