[layer8]

> If someone is pessimistic but his description of the world matches REALITY, then there's nothing wrong with his view point.

A description that matches reality is realist, not pessimist.

[threethirtytwo]

Technically this is true. Practically speaking most realists are perceived to be pessimists. There are tons of scientific studies to back this up as well. People who are judged to be pessimistic experimentally have more accurate perceptions of the real world.

This means that most people who you would term as "realists" are likely optimists and not realists at all.