Sometimes, we ought to pity on people who view blindly.
Even if you are not very good with computer, you will not causally judge someone who is sitting in front of the computer as “free and nothing to do” without even looking at the screen at what he is busy with.
We simply live in a world where there are too many shallow people. It is pointless to be angry; moreover, they are probably just passing causal remarks and not doing it on purpose.
We have to learn to live with ridiculous comments.