"Could it be that standards are falling that low over there at the Telegraph?" Alas, Monsieur Frogman, these are not fallen standards. The standards re: Communism have been this low since the '30s. In the West people were slow to recognize the Soviet state for what it truly was; Winston Churchill is one exception who comes readily to mind. Oddly, George Orwell was another, going "off the socialist reservation," as it were.
For seventy years at least, the standard line is that these were idealists who got carried away, and that any atrocities were regrettable, isolated incidents in pursuit of a noble goal. It's easy enough to believe because evidence to the contrary (such as the four you cited) becomes one more regrettable, isolated incident. This does involve a large dose of self-delusion, but that's the easy part. Association with a "bold movement," especially one whose power wanes, gives all the required thrills and self-approval for people with a taste for faux-martyrdom, and sweeps aside any doubts. They also get to murmur to themselves, "Of course, if I had been in charge it wouldn't have been like that at all." One gets the cache of approving of the Movement while rising superior to its flaws - truly a triumph of escapist thinking.