You feel that way because you're on the Internet. I've never seen the movie, it was way before my time, and it exists in the tiniest amount of public consciousness today. The only reason I know what Soylent Green even means is because people on the Internet reference it occasionally.
I've talked to quite a few people about Soylent and I've said "you know, like the movie" and most of the time they have no idea what I'm talking about.
Besides, it's not called "Soylent Green". Green was the cause of the shock twist in the movie, but there was also Soylent Red and Soylent Yellow in the movie, which were pretty much what Soylent, the product, is trying to become.
The name is appropriate in the context of the movie, although I would have never chosen it.
I've talked to quite a few people about Soylent and I've said "you know, like the movie" and most of the time they have no idea what I'm talking about.