Why is the stuff of the world bad
Man sinned. Man got kicked out of the Garden. Man lost God's protection. Now, even though space is beautiful, with all of its stars, we don't trust God to protect us physically if we open the hatch and go for a dive in a 0 degree Kelvin vacuum.
Life now is transient. We live. We die. God gave us life. And he promised Adam death. So there's no real point in God protecting this decaying body, is there? But you can be sure he'll protect the next one once we are resurrected and live for eternity again.
Why is there bad stuff in the world? Because God's plan is unfinished, and because our free will threw a monkey wrench in God's plans. One day his plans will be completed in spite of us, and the results will be beautiful.