Because it is relatable to a lot of viewers. Viewers of the show often have depression, which is different from just having shit life syndrome. The two often go hand in hand but are not the same. The scenarios in Mr robot are depression scenarios, not shit life syndrome scenarios.

Shit life syndrome is having no job, having no love, having no hobbies, having no money, etc. Does this make people depressed? Yes, often times. Is this a requirement for depression? Not in the slightest.