There is a reason why people are suicidal. I'm sure Kakashi's father would want to join IT.
Oh really, then why did Kakashi who had an even more miserable life do everything in his power to stop it?
IT is a foolish not to mention childish way out for people who can't handle reality.
It strips the world of its ability to develop and change, human civilization changes as time progresses and new ideas are born, new technologies are created, science improves.
Also it takes away the ability to enjoy good things, the reason people enjoy the good moments in life are because there are bad moments, not to mention that the whole concept of a dream requires there to be hardship in life.
A dream is something people want to achieve that requires hardship and work, it is born from a desire to go beyond what one already has. If that dream is not earned then that dream becomes meaningless.
IT strips one of their ability to develop and grow, to learn and get stronger, development requires hardship and work.