Earlier quoted context omitted.
It's a reference to "Say what you like about Mussolini, he made the trains run on time." This quip is generally used sarcastically or wryly. "Say what you like about [something that's seriously bad], at least [frivolous matter] has improved."
Actually it’s a joke about concentration camps and it’s in bad taste and offensive.
No it isn't.
Gorgoiler says "a common English aphorism about punctuality on 20th century Italian railways" and links to https://www.economist.com/science-and-technology/2018/11/03/... Both are clearly about Mussolini making trains run on time (or rather, not actually doing so.) Wikipedia describes the origins of the quip as such:
> Mussolini was keen to take the credit for major public works in Italy, particularly the railway system.[109] His reported overhauling of the railway network led to the popular saying, "Say what you like about Mussolini, he made the trains run on time."[109] Kenneth Roberts, journalist and novelist, wrote in 1924: "The difference between the Italian railway service in 1919, 1920 and 1921 and that which obtained during the first year of the Mussolini regime was almost beyond belief. The cars were clean, the employees were snappy and courteous, and trains arrived at and left the stations on time — not fifteen minutes late, and not five minutes late; but on the minute.[110]"
The dubious premise of Mussolini being responsible for reliable trains predates the Holocaust.
As for "it’s in bad taste and offensive", I agree that comparing fascism to systemd is in bad taste.