Generally, people on this site will say not to entertain "debates" in general and that can be pretty good feedback.

For your edification though, here are a few points to consider. These are all, pretty much taken from :parenti: 's Blackshirts and Reds or Against Empire

• Question the premise. Is it true that soooo many people left? The US and the west ALWAYS play up any individuals that leave a "communist" or "socialist" country. In fact the US has a policy of mostly taking in refugees from these countries. The US rarely, if ever, takes in refugees from people fleeing their puppet regimes. It would make them look bad (Chile and much of South America is a great example)
• Parenti does say we need to be honest with ways in which people in the Soviet Union were dissatisfied with not having access to "the latest fashions, or Jordans, or whatever the fuck materialist thing you want to put here". But he points out that once the Soviet Union was dissolved people yearned to have it back. They took for granted that their basic needs were taken care of. It should also be noted that the Soviet Union was driven to ramp up military spending early on due to the hostilities of the West. They would much rather have spent funds on other things, and even had discussions with the West about trying to dial back hostilities so they could devote efforts on things other than military spending. But the west said fuck you.