I believe that unless you are chemically, neurologically or biologically imbalanced, there's no excuse to be bitter or unhappy. I won't discuss happiness here, but even if the advice of some bitter person is good, I would say that an advice of a person who I lookup to will always be "better".
Of course, things should be placed in context. An advice of a bitter math teacher on mathematics will always be better than an advice from a happy ignorant person.
On a personal note, don't be bitter. You can accomplish the same without the bitterness, it's just weighing you down.
It means the parent post assumes the world can be pigeonholed in whatever criteria he thinks/has been taught to be ideal. Anyone who doesn't fits there is abnormal in some way.
He assumes there is no reason to be unhappy, completely ignoring the various reasons I have pointed out and stated that ignoring them would lead to bliss, but that's not what I seek.
Of course, things should be placed in context. An advice of a bitter math teacher on mathematics will always be better than an advice from a happy ignorant person.
On a personal note, don't be bitter. You can accomplish the same without the bitterness, it's just weighing you down.