Traitorfish
The Tighnahulish Kid
Well, in the first place, that's an electoral strategy, not a political program. An ability to work together to achieve certain concrete ends doesn't imply a specific end-goal- indeed, the very phrasing of your example, an alliance of communists, socialist and radical liberals, emphasises that it does not.It kind of does though. Worker protection laws in France are what they are because at several key moments (1936, 1945, 1981 and 1997 most notably) the left managed to unite (with communists, socialists and radicals (which is a center left party)), win the elections and enact the necessary laws. Some of which were utopian in their times.
In the second place, the relative strength of France's worker protections does not imply socialism, and indeed, France in 2017 falls far short of the hopes of even the most moderate of 20th century socialists. Whether somebody wants to kill the rich or cooperate with them, the left's current stunted ambition of achieving grudging tolerance by the rich can only be a disappointment.