Well I suppose it's impossible to determine real motivations of politicians, but I always assumed this was simply BS that nobody in power ever really believed.

I mean, when you're addicted to cheap oil/labor/whatever but the regime with the cheap oil/labor/whatever has some pesky anti-democratic tendencies, what better way to sell it to a skeptical population than to tell them that by merely consuming the cheap goods the transaction itself will somehow change the problematic regime's ideology?

Frankly this is true in the US too. It's true everywhere in the west, where there are inexplicable enclaves of Russophilic sentiment that flies in the face of all reason and evidence. Tech bros think they're a great new market. Finance wonks think they're a regulatory backdoor into European money. Old guard tankies still think they're anti-imperialist heroes. Reactionary right wingers think they're ethnic paragons fighting the culture war the west is too afraid of. Name a demographic, and you'll find a pack of sincere Russian apologists hiding in it somewhere.

When the history books finally get written once all the partisans are dead, the ability of this tiny, shrinking Russian state to effect this kind of information war is going to be the subject of book after book.