Comments

One thing I have found with a lot of people who are bothered by what others do is that they have a lot of insecurity with themselves or they grew up being judged a lot by their family. If they are insecure, they take their insecurity out on others by judging them for being themselves and doing things they feel they cannot do. If they where judge by their family a lot growing up, they feel a need to also judge others and fit them into that conformity. That doesn't make it right what they're doing, but it does add some perspective on why they're doing what they're doing. 

However, what you said is absolutely true, it's their life and nobody should judge them.

Truth. These people are so annoying, they have to mind their own business and accept people as they are.