Homeschooling a Calling, I'm not so sure

I used to believe homeschooling was a calling.  I think a lot of people use this verse as their basis for their "calling":

“And these words which I command you today shall be in your heart. ⁷ You shall teach them diligently to your children, and shall talk of them when you sit in your house, when you walk by the way, when you lie down, and when you rise up. ⁸ You shall bind them as a sign on your hand, and they shall be as frontlets between your eyes. ⁹ You shall write them on the doorposts of your house and on your gates.  (Deuteronomy 6:6-9)

I like the points from this source:

First, and perhaps most obviously, these verses do not directly command formal homeschool (in the sense that homeschool is practiced today in Christian circles).
Rather, they instruct Israelite parents to consistently teach their children the things of the Lord within the normal activities of life. The passage says nothing about subjects like reading, writing, and arithmetic.

Second, Deuteronomy 6:5–9 is an Old Testament passage. Even if the passage instructed the Old Testament Israelites to practice formal homeschool (which it does not), such would not be a binding command on New Testament believers.

And this one:

“Sons are a heritage from the LORD, children a reward from Him.”
(Psalm 127:3)

And this one:

Train up a child in the way he should go,
      And when he is old he will not depart from it. (Prov. 22:6)

 My problem with thinking of homeschooling as a calling and using the above verses is that - aren't Christian parents (all of them) called to teach their children about God and His ways?  

Can we say that we are "called" to teach our children math at the kitchen table?  I don't think so.  Can we say that we are "called" to teach our children about God and his commands?  Yes.  Because the Bible says so.

If you are going to tell me you are called to preach the gospel in Africa - that is something I can get behind.  Why?  Because of Matthew 28:18-20:

Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, ²⁰ teaching them to observe all things that I have commanded you; and lo, I am with you always, even to the end of the age.” Amen.

I don't see any clear verses in the New Testament that says we are called to school our children at home.  And in fact the verse in Deuteronomy doesn't say anything about the three R's.  But if you see them let me know.  Don't be upset at this post.  I hope it makes us all think about the words we use and how we throw them around.  Being called by God is a very serious thing. 

Parents everywhere should teach their children about God and about Jesus Christ.  They should model Godly behavior.

Please don't think I am attacking you, I just want to make us think about why we say the things we do.  Are they actually biblical or have they been said so many times that people just think they are biblical because we use biblical language?

I am not saying homeschooling is wrong, just that it is a choice.

Thoughts?  Please use nice words.  I am open to convincing otherwise if you can provide correct Scripture in context.

Homeschooling is not the salvation of our culture. Jesus is. Homeschooling will not make a family successful. Jesus does. Homeschooling will not keep a child from rebellion. Jesus does. Homeschooling will not keep a marriage strong. Jesus does. And the minute, I think that homeschooling will do any of these things, is the day I begin the slide toward defeat. Homeschooling will not build a successful family any more than a hammer will build a successful house.  (Source)

Good reads:
Homeschooling is NOT the Gospel
Homeschool Blindspots
Does the Bible mandate homeschool
The Weaker, The Stronger, The Homeschooler
**What is God Calling Me To?