Yea, the government might be able to trace who owns what coins... but how can we... how can we as regular people avoid buying some centralized piece of crap coin, with absolute certainty.
I think no coin worst. Increase and decrease are normally situation. We just wait for many time until the coin rising again. Be patient please 
Any investor or anyone who wants to buy a coin and cannot go through doing some thorough research is then definitely not ready to invest. When you do this, then at least you will be able to deduce some facts you may need, while putting few stuffs together.
But there is no centralized coin that won't be glaringly centralized. We just have to research about the coin and find out for ourselves. For example, XRP is a centralized banker's coin but do you know that? You cannot know unless you have decided to read some few things about XRP or probably from little readings here and there bump into it. That is just the only way you can know.