Why is it important to defend the KJV when it’s really not a salvation issue?

“Why is it important to defend the KJV when it’s really not a salvation issue? All believers go to heaven regardless of which bible they took to church, right?
1.) Because Jesus Himself said that the issue is important. (Mt. 4:4)
2.) Because salvation isn’t all there is to the Christian life (Lu. 4:4)
3.) Because Jesus Himself said that we are to teach “all things” that He taught (that would include all the words). (Mt. 28:20) Thus, for discipleship purposes (that’s beyond salvation for sure), we need an every-word-of-God Bible available and accessible.”

Peter Heisey