One of the reasons for the shows popularity is the controversial nature of Hannah and her storyline.
Here are the facts that support this theory:
1.We never see Hannah explicitly struggling with mental illness.
On its own, this isnt a big red flag, mental illnesses come in many shapes and sizes.

The tapes are red flag #1, image via13 Reasons Why
2.The mere existence of the tapes.
3.The tapes are intended to be passed around.
This makes her outing her former friend Jessica as a rape victim in tape #9 extremely troublesome.

Why would Hannah put her friend on blast?
This seems deeply disturbing and cold-hearted on Hannahs part.
4.The series makes it clear that everyone in Hannahs tapes have their own issues.

The tapes are red flag #1,image via13 Reasons Why
These two things create some dissonance.
5.Sociopaths are smart people with good social skills.
Although Hannah claims to be an outsider, we are bombarded by evidence to the contrary.
We see her being likeable and well-liked.
Everyone else who has been to high school knows this isdefinitelynot the case for most people.
6.She plans for Bryce to get the tapes near the end.
If her intention was to show people the hurt they caused her, he should be first.
Her actions show she is interested in hurting as many people as possible.
I really hope season 2 addresses this.