One of the biggest problems with how mental health is treated on tumblr is the obsession with disabling, as opposed to the healthcare professional's focus on enabling.
On tumblr, the focus is on comfort, safety, and expecting the world to adapt to your insecurities. It wants the mental ill health sufferer to fall into their illness more - reinforcing and adapting to their negative cognitions - and allow it to become the most fundamental aspect of their person. This is usually done under the guise of "acceptance", and is usually done out of misguided kindness.
In the healthcare setting, the focus is on challenging negative cognitions, acclimatisation with the things that the individual finds difficult. In contrast, its focus is on enabling the sufferer to thrive and develop beyond their illness, and become as capable in wider society as anyone else. In spite of their illness holding them back.
Tumblr is concerned with denying mental ill health and removing capacity from the individual, whilst the mental health professional is concerned with adapting cognitions to enable individuals with mental health problems.