I have atheist friends, atheist relatives and used to call myself atheist too so i know that. (Now i call myself agnostic with spiritual leaning)
The problem is that these kinds of atheists are very common and vocal online, and they affect youth today. I find it just as scary as the spread of racism or religious extremism. Any cultlike "us vs them and if you're not exactly like us you're better off dead" type of movement is inherently destructive, and on top of that makes the ideas they hold look really bad. The westboro baptist church makes christians look bad, militant internet atheists make atheists look bad, misandrist tumblrinas make feminists look bad... the list goes on.
Basically i will respect most political and spiritual beliefs as long as they are not destructive or extremist. I have no respect whatsoever for disrespectful, irrational and plain dangerous assholes.