The following is a Bible based answer. This is what Jehovah's Witnesses believe.
Creation and the eviction of rebellious angels from heaven did not occur at the same time. The angels were in existence before the creation of the earth. (Job 38:4, 7) The earth has been given to mankind as a home, not a testing ground. (Psalm 115:16, Psalm 37:29)
The eviction of rebellious angels from heaven did not happen until Jesus was appointed as the king of God's kingdom. Under inspiration, David helps us to see that at some point, the Messiah would receive a certain amount of authority, but that after this he would still have to wait for a period of time before given authorization to act against his enemies:
Jehovah declared to my Lord:
“Sit at my right hand
Until I place your enemies as a stool for your feet.”
In Acts, the Bible helps us to see that this refers to Jesus sitting at God's right hand after being resurrected back to heavenly life, and that even after that, there was still a waiting period before he would act against his enemies:
God resurrected this Jesus, and of this we are all witnesses.
Therefore, because he was exalted to the right hand of God and
received the promised holy spirit from the Father, he has poured out
what you see and hear. For David did not ascend to the heavens, but he
himself says, 'Jehovah said to my Lord: "Sit at my right hand until I
place your enemies as a stool for your feet."'
Bible prophecy and world events point toward the year 1914 as the year when Jesus was anointed to king of God's kingdom and he acted to evict Satan and his angels out of heaven, with Satan thereafter being confined to the earth. (Revelation 12:7-12) The idea that this did not occur until the start of the "last days" is supported in Revelation 12:17 when it brings out that once the Devil is confined to the earth he knows he only "has a short period of time" remaining. (2 Timothy 3:1-5) That means that we can rejoice because the time of living under Satan's "system of things" is nearing its end. (2 Corinthians 4:4) After that mankind can fully enjoy the earth as their home with God's physical and spiritual protection and blessing! (Revelation 21:3, 4; 1 Corinthians 15:26)
For more information look at this related question in the "Good News From God!" brochure: What is God's Purpose for the Earth?