It depends what you define as an achievable goal for them, but considering the FIFA ranking, they are right now ranked 57th between South Africa and Saudi Arabia. it is not bad for a small nation, or they are not that small with their population of 35 million, but they are considered rather small in the football business.
Whether there acceptable ranking has to do with their USSR past, I don't know, but it is true that countries from that region put a lot of emphasis on sports. I personally didn't know football is a big thing there.
The FIFA ranking is misleading sometimes I think because when you argue that Uzbekistan is enthusiastic about football and sports, China is as well, but they are only ranked 94th.
Uzbekistan has hardly played against any teams outside the AFC confederation. So the current rankings doesn't really take in to account their present form. Only when they play against the top teams in tournaments such as the FIFA World Cup, their performance and prospects can be accurately measured. But I would like to repeat one thing. Performance in international football seems to have some correlation to demography. Countries with a young population are the ones who are advancing the most now.