Why is it wrong to say that the entire Bible is not infallible?

It isn't wrong.  The Bible has its problems -- but it still contains SOME of the word of God.

Mainly because the entire Bible is the written Word of God. God neither lies nor does he make errors.

The actual message of the Bible is infallible when subject to authoritative and accurate interpretation. Obviously it is not infallible in the absence of authoritative interpretation, as the doctrinal chaos of Protestantism clearly demonstrates - thousands of manmade denominations, each claiming to follow "the Bible alone", yet the beliefs/teachings of each denomination contradicting the beliefs/teachings of the others. Truth cannot contradict truth, so untruth is obvious y rampant in this unauthorized manmade tradition. Which is why Jesus Christ founded just one Church, said it was to remain one, and promised that one Church "The Holy Spirit will guide you into all truth", and "Whatsoever you bind upon Earth is bound in Heaven", and "He who hears you hears Me". Which is why that one Church remains one in belief, one in teaching, one in worship, one in biblical understanding throughout the world after 2,000 years, with no conflicting denominations.

The entire Bible is NOT infallible.  It is full of errors, inconsistencies, and contradictions.

Because God is well able to preserve His Word.  And He did.  I think the problem may be  the definition of "infallible."

What I mean is, God does not necessarily approve of everything that's in the Bible; for example, slavery and children dying.  The Bible just tells what happened.  There's a lot of history there.  There are many spiritual lessons to be learned from the Bible; for example, it clearly shows what sin is and its remedy.  

The Bible is infallible when properly interpreted.

Because the books in it were all written by fallible people. The books in it were then translated by fallible people into a second language. The books in it were even then translated in some cases again by infallible people into a third language. The books in it were then selected by fallible people from among numerous books to be in it. The books in it were then translated again by fallible people into a fourth language, English. And all those people were of course all fallible people because the only infallible person to have ever lived is Jesus, and he didn't write any books.

Even just look at how many different English translations there are, the English being translated from Latin, the Latin being translated from Aramaic, and in some cases, into Latin from Greek that was previously translated from Aramaic. Translations are only ever approximations of meaning, never exact, never able to convey the exact meaning because words don't have identical meanings across languages and cultures. Even a word as simple as "house," for example, conjures a completely different image in people's minds in English-speaking America than it does in Hebrew speaking Israel, never mind that the word "house" has all these other meanings in English, like family (e.g., the House of Windsor), like casino, like theater (e.g., the house lights dimmed), like a church (e.g., a house of worship), etc., and then imagine that Aramaic was the same way, a whole plethora of meanings for whatever word for house was used, and then Latin being the same way, likewise with a whole plethora of meanings, and that's outside the fact that the mental image conveyed by the word is entirely different even when it does meaning a dwelling people live in, an inference that must be made by a translator each time it gets translated-- all of that is just with a word as simple as "house," so what when we come to words of greater nuance and many more meanings and to idioms? It's impossible. Capturing the exact meaning in translation from a dead language spoken thousands of years ago into a modern language is impossible, the best that can be hoped for is an approximation, and in those approximations, there is fallibility, unavoidable fallibility, even. That's why there are so many different translations in English, for example, not because they are in conflict but because where there seems to be conflict or discrepancy, there is more than one way to interpret the original text, or the original text has double-entendre or nuances that no single word in English captures.   

Anyway, the reason there are so many books in the Bible is so that by many, many fallible people striving to deliver and bearing witness to the gospel through accounting and translation, we are able to suss out the gospel's infallible truths from the fallibilities of the men who did their best to convey them. That's why there are four gospels of Jesus, four separate accounts, so that when the gospels corroborate one another, we know that that's true, just like if you have four witnesses all independently give corroborating accounts in their own words. 

You can say whatever you want, but you will be held accountable to all of the things you say, by the Lord Jesus Christ Himself if you die as an unbeliever.  The King James Bible is 100% perfect, 100% infallible.  The Bible is the Word of God.  The Lord Jesus Christ is God, and He loves you.  Believing in the Lord Jesus Christ means being forgiven all sins past and future, and means going to heaven and not hell.  Death leads to immediate heaven or hell, and it is too late to be saved, after death.  All believers still sin.  See 1 John 1:8.  To be in heaven and not hell, believe in the Lord Jesus Christ, who is God and who died on the cross and shed His blood to pay for all of our sins in full, and who was buried, and who resurrected from the dead.  The only way to avoid hell is by believing in the Lord Jesus Christ, without adding any of your own works.  See Romans 4:5, 1 Corinthians 15:3-4, and John 3:16.