Remember, the social Democrats sided with the Nazis over the socialists. They’ve done it every time they’ve been given the opportunity, and will continue to do so as many times as people fall for their shtick.
“The master's tools will never dismantle the master's house."
-Audre Lorde
The dissolution of the soviet union caused quite a lot of economic issues in countries more integrated into it's economy so a poll that says a country was harmed by the dissolution isn't saying much. I'm pretty sure quite a few German citizens would say they were harmed by the fall of the Nazi regime when it fell, that has no bearing on which was better or even which people prefer. Also in the poll for that source it seems the most anti USSR countries were skipped for some reason.
Also the living standards of 2011 Lithuania and Ukraine must have been pretty bad, I'm assuming that would also be the case for countries like Moldova too but that study only covers the 3. Lithuania is a bit of a surprise though but I doubt the numbers are anything close to that now as quality of life in the baltics has improved massively since the USSR.