His world, the Asgard, was destroyed. His hammer was smashed into pieces by his sister, who turned out to be an evil war-obsessed psychopath, also she killed his best friends. He lost his eye. He lost his mother, than the father. All the asgardian people was killed by Thanos.
And, the most sad, he lost his brother. He watched Loki dies three fucking times. And every time he could do nothing.
Why does Marvel hate Thor so much?