If no one other than the 6 people you're working with have ever read the code and nobody wants to add code to it, you need to really spend some time reading the code before you make a judgement call. At that point, it's better to make the code not shit than simply call it shit.
In software, if you can articulate why it's bad, you can fix it. If you can't articulate why it's bad, keep it to yourself.
We need more developers like Torvalds - not because he's nice, but because he's terrifyingly experienced and completely honest in his feedback. I couldn't think of a better mentor.