While there are many reasons behind the Soviet Union's collapse, one recurring motif is worth pointing out. Often, the response to the failure of a reform meant to lead to a more pure form of socialist organization was that the reform didn't go far enough. Limited successes were viewed as confirming the course was correct and the problems, which to an impartial observer outweighed the successes, were seen as being something that would be fixed by applying a more pure form of the ideology.
This is something to think about whenever the argument is advanced that a reform failed because it didn't go far enough. This may be true, perhaps a key part was left out that was an essential to success or there were other factors involved that were temporary and would not apply to future reforms. However, it is much more likely that the limited success of a reform, and likely the relatively greater problems caused by it, indicate not that the reform did not go far enough but that it is fundamentally flawed and side effects not originally acknowledged outweigh the benefits of the reform and will only get worse if a more pure form is pushed towards. Something to remember about any effort at ideologically driven reform.