I don't think anyone likes censorship, especially artists! Unfortunately, The Cure have been dealing with a severe misinterpretation of this song since it came out in 1979. Even though it was their first single, they agreed to leave it out of lots of promos, radio spots, etc at the time.. they were after all still a college aged group trying to make it big in the music industry.
The song appears in live shows here and there for the next 20+ years uncensored. When I was in high school we read "The Stranger", analyzed it in great depth (can you even study/learn about existentialism without that book??), and then listened to the song in class as well.
The Bestival 2011 show in France was a special case. Robert wasn't going to play it at all, but ended up doing it as the very last song during the encore. Seeing as how just five months before the festival many people were killed by a suicide bomber in a Moroccan cafe, Norway had just suffered the deadliest attack on them since WWII, AND the "Bestival" Cure set took place 09-10-11, Robert was quoted as saying he thought changing the lyrics for THIS show to "Killing Another" was quite fitting.
Last year in Hyde Park for their 40th celebration show they played it regularly. In any case.. it not being on Spotify is the labels fault. They've been at it for 40 years!
(PS Do yourself a favor if you haven't already and listen to the 2011 live set. The second set and encore are.. mad dark sounding. It's **bleep**ing fantastic.)