Because they do not want or can’t homeschool..
For most of the people I know it is because they “do not want”...it would inter-fear with the way they want to live...letting their children be brainwashed is just so much easier...
Unfortunately most people have such a short range outlook. They live for the moment and don't really plan for the next generation or two.
Proverbs 13:22 A good man leaveth an inheritance to his children's children: and the wealth of the sinner is laid up for the just.
Psalm 103:17 But the mercy of the Lord is from everlasting to everlasting upon them that fear him, and his righteousness unto children's children.
So if we follow God's plan as told us in the Scriptures we should be planning on leaving an inheritance of righteousness unto our children's children...and it seems to imply that there will be some wealth involved as well. But instead most are living for themselves...more in line with...
Isaiah 22:12-13 The Lord, the Lord Almighty, called you on that day to weep and to wail, to tear out your hair and put on sackcloth. But see, there is joy and revelry, slaughtering of cattle and killing of sheep, eating of meat and drinking of wine! “Let us eat and drink,” you say, “for tomorrow we die!”
And when we live only for ourselves it leads to...
Exodus 34:7 “...maintaining love to thousands, and forgiving wickedness, rebellion and sin. Yet he does not leave the guilty unpunished; he punishes the children and their children for the sin of the fathers to the third and fourth generation.”
So if we live for God there will be blessings for us and our children, but if we live for ourselves we will leave a legacy of punishment. As a culture we have embraced the idea of the “Me generation” and “if it feels good do it” and “I am spending my children's inheritance”. And then with children growing up in this environment we wonder why this country is in the shape that it is.
Sorry for the long response to your short ping...sometimes I just need to get on my “soapbox”.