A very good friend of mine is in the midst of an avalanche of work. He has a lot of open contracts, and has been abandoned by a fellow developer that was helping him with his workload. So, with three huge clients breathing down his neck he has been working non stop for weeks now.
One client contacted him about the iPad application he is building for them, he let him know "I paid another developer to look at your code, he says it really sucks."
When he told me this story, I had to chuckle a bit, and think of all the times I had decided that other people's code sucked. When I first started out, and I looked at code that definitely sucked hard, I scrapped it, and started from scratch in a way I knew was way better. As I matured I looked back and realized that what I had destroyed was a well accepted design pattern, and what I created was a mess of a mess pattern.
After some growth I encountered code that I thought sucked ever so often. At this point I wasn't decimating things all together, I would find specific parts of code that I found intolorable and rewrite it. About 9 times out of 10, when I got more than halfway there I'd run into an issue that made me say "Ooooh, that's why they did it that way" and revert it or use the same "sucky" logic with my syntax.
Now that I am a little more seasoned, I can tell you with all confidence that I never look at a solution that someone else created and say "Oh, this code sucks." I know that there really is no quick way to tell if code is good or bad without understanding the entire solution. Sure, sometimes things can look sloppy, or poorly done, or undocumented (in my case, not self documenting), however, you never know what was going through the head of the developer that wrote it. More often than not there is a reason why they have done things this way, and there is no hard and fast way to tell what the context is without being elbow deep in it.
So, when I hear that someone has looked at someone else's code base and determined that it sucked I smile and remember what it was like to be so new and sure of myself. So sure that I was an amazing developer, and that I knew what was best in every problematic situation. I miss that swagger, but I appreciate what I have learned, and that is the only person's code that sucks is my own, and the reason why it sucks is I just haven't learned how to make it better yet.