Has Tim LaHaye?

You've completely missed the point. The point is that Jerry Jenkins wrote terrible books and the Christian community has embraced them like they're the greatest things since sliced bread. Embracing such hideous writing makes us look like fools and not for what we might consider the right reasons. There are people who have watched, and continue to watch, Christians promoting and extolling the virtues of these books and determine that they want nothing to do with people who read such garbage and think it's good.

The main difference between Stephen King and Jerry Jenkins is that one of them is a good writer and the other is not.

Yes, it is important. In Left Behind, the 4 main characters get saved after the Rapture. As I understand the pretrib position, once the Rapture happens, those who are left behind are subject to what is said in 2 Thessalonians 2:11-12:

L&J have conveniently ignored that Scripture.

If the pretrib position is true like Left Behind says it is, then a false hope has been presented to non-Christians. They will be able to say, "I don't have to get saved now. Once the Rapture happens, I can get saved then." The problem is that the call to salvation is today. Not tomorrow. Not next week. Today. The idea of, "I can wait to get saved until after the Rapture because once it happens, I'll know Christianity is true and then I'll believe" is very dangerous.

JD had the perfect answer to this.

I would rather that people learn of, and fall in love with, the Christ of Bible, not the Christ of Left Behind. You think they're synonymous. They are not.