There's another PoV to this labelling. Many times, a person having an opinion to the contrary of the other is labelled an armchair warrior just because their opinion is contrarian.
There are times when people have actual experience but are delusional
(a human being is involved after all) about that experience. When that delusion gets called out these labels start flying. In such cases, what makes the delusional but experienced person right and the person calling him/her out, wrong
(or an armchair warrior)?
Just experience does NOT make a person right which I'm sure all of us have seen in our professional life. Just as theoretics does not provide all answers.
Edit:
And to those who stop posting just because they think they will get a negative reaction to their posts - think again and learn to take this in your stride. It's only the internet after all.