Why is it, if people suspect someone has a mental illness they taunt them ?

Because people who do that kind of thing are dimly aware they are the dregs of humanity, and figure if they can drag somebody else down, maybe they'll move up a little.

Education. Until a person learns better, they can’t do better. By taking mental health out of the darkness and realm of myth, we can better discuss and understand the topic and those affected by it.

Here people look away and avoid the person. Nobody wants to address the issue and rather pretends it doesn't exist.

We should try to feel compassion for these people too. I feel often if people have never experienced care, they don't know how to feel that or reflect it back so they are lacking the grounding and insight to recognise what they are doing. Sometimes they are just showing their own hurt in the only way they know how.

Self righteousness? Most humanoids love pointing out others [perceived] flaws or weaknesses that make them feel superior. It diminishes the other persons value and boosts their own false self esteem. Sometimes could be projection even.

I think people are afraid of what they don't understand. In their needing to make some sense of it, they elicit their same thinking, fear and judgment from others in an attempt to quiet their own discomfort.

Not sure. It's true tho, many people throw rocks at the person who is struggling.

It’s a sickness people have about asserting superiority!

Simply because people do not understand

Some people are just f#cked in the head.

When I was a kid starting a new school. All the other kids were calling this one boy, "One hundred Ring holes". He had been raped, and when his attackers were done they inserted a Squid jig up the boys' backside. And the kids in school were teasing him for it... I say again, some people are f#cked in the head.

some peoples hearts have turned to sauce

Because the world is a piece of shit.

Cruelty seems to be the go to behavior for people lately. Cruelty for the sake of it.

Human nature is such that we attack weakness. Some have enough empathy and understanding to behave differently, but many dont. Natural selection demands that we ostracize the weak and drive them from the gene pool.

People that do such are not only highly insensitive but extremely immature and intelligent as well as lacking empathy.

people like that exist now unfortunately, but i know no one like that and would avoid degenerates at all cost.

It’s because some people enjoy being cruel.

Because people are jerks

People with their own unresolved problems do the former, because they feel better when someone else is suffering.
Those who are well-adjusted calmly approach the person as you’ve suggested. They have no need to hold the person up to ridicule and can afford to show some compassion.