You're describing only one small, albeit vociferous, section of 'the left.'
Much of the radical left came to prioritise 'anti-imperiailsm' out of a distant (possibly subconscious in many cases) recognition that socialist revolution, and possibly any form of wide-ranging socialist reform, had slipped off the agenda, probably for good, in the capitalist heartlands. It often does involve tacit or even overt support for some dark forces, and the fact that if they succeed they are usually there to stay is brushed over or simply ignored ('the working class' will rise up against them eventually.) But it also arises from the fact that those dark forces are usually the only ones effectively resisting the havoc caused by western, and particularly US, interference all over the globe, especially when, nowadays, it is forgotten that it was liberal right (and soft left) regimes in the west that routinely supported and armed to the teeth 'fabulously corrupt, homophobic racist and anti-semitic dictatorships' in the name of anti-communism. That the liberals of right and left can now go around posing as the forces of liberation is particularly galling, particularly in those countries which were the targets of the despotism the west supported.
Neither the left nor the liberal right has really come to terms with the chaos of the post-Cold War world, both within their own societies and internationally, more than thirty years on even while this chaos was entirely predictable.