The translation process would have gone:

1) root of all evil is greed [eliminate non-English articles]

2) greed is root of all evil [swap to SVO syntax]

3) greed is the root of all evil [add required English article]

4) The love of money is the root of all evil ["translate" the vocabulary word into simpler terms]

There simply isn't any more faithful way to render that thought. You could stop at step three, but the KJV's genius lies in what a small vocabulary it uses. (I just checked: "greed" appears nowhere in the KJV, so the word was on the hit list.) The goal was to make the text understandable to the broadest audience possible - the vast majority of whom, at the time, were uneducated. That the translators were able to maintain that constraint while also creating something of incredible literary power is awe inspiring.

If you want to break it down a bit further, the phrasing in step three puts two stressed syllables ("greed is") together, which can be awkward, while the final version puts the verse into an iambic pattern (unstressed syllable preceding a stressed syllable), which rolls off the tongue much easier. The word "evil" then reverses that, which breaks the rhythm and calls attention to the end of the thought. (And, maybe, if you want to get especially literary or theological about it, provides a subtle commentary on the nature of evil.) It's so good.