You are the company you keep.
This phrase holds many truths. If you allow people who do not share your values disrupt your life, you can find yourself in a very awkward place. However, this should not be mistaken for being judgmental. While the two are easily misinterpreted, judgement has a much more negative connotation.
Many people stand and watch their friends give in to the pressures around them, unable to say no to substances like drugs and alcohol. However, even if you disagree with their actions, this in no way means you should treat them poorly. After all, they're still people.
Remembering your value system and keeping your truths is essential, not judgmental. However, only seeking out people who are like minded to yourself can leave your world a small place. Since there are so many different people from diverse backgrounds, it's important to expand your knowledge of others.
In the end, we are all just people doing our best. As English actress Kate Winslet said, "It's very easy to be judgmental until you know someone's truth."