Consider that you might be wrong. It takes a lot of work to understand a code base. I've seen many young developers spend a short time looking at some code, fail to understand it, throw up their hands and claim it's a mess that needs to be rewritten. Put in the time to make sure you know what you are talking about before making a fuss. I've refactored a lot of other people's code in my career. If someone else wrote it then it pretty much always looks bad at first. Then again there is plenty of genuinely bad code out there.
