Since you seem to be asking about economics, I'll start with that. You are right to say that the Soviet economy was bad, but at least it was relatively stable. People had gotten used to that economy and how it worked. When communism fell, all of a sudden people had to try to adjust to a new system without communist control of the economy.
When this happened, the Russian economy fell apart because no one really knew what to do in a system where the governent wasn't telling everyone what to do. The Russian economy went into a deep depression with somewhere more than 40% of people living in poverty. This, of course, led to all sorts of social problems such as increases in alcoholism and suicides.
So, just because an economic system was bad doesn't mean it cant get worse. After communism fell, what had been a bad, but stable, economy became a much worse economy with no stability.