why don't preachers say much about the old testament?

I understand that Jesus is a very crucial part of Christianity, but there are many other books that get consistently ignored.

Here are the books that are preached about, in my experience:

Genesis, Exodus, 1 & 2 Samuel, Psalms, Proverbs, Isaiah, the Gospels, Acts, Romans, Hebrews, and Revelations.

Why does nobody ever talk about the following:

Ruth, Nehemiah, Kings, Chronicles, Judges (sort of), Numbers, Leviticus, and the Minor Prophets.

The minor prophets books are small, but they are pretty jam packed full of information.

Yes, the New Testament is for today, but the Old Testament is like the base. It really just seems to be ignored, in favor of dogma that grandpa talked about.

We have so much information at our disposal, and it has caused somewhat of a revolution in Christianity. Dogma still rules though.

Maybe they would run across something they can't explain, and would therefore lose credibility?

I don't know for sure of course, which is why I am asking here. A place where there are many different Christian views.

What are your guys thoughts on this?