L. Ron Hubbard didn't write all those ten novels, unless you believe he wrote them from the Other Side. He was dead. The first couple of them may have been ghostwritten, too, I don't know.
I started reading SF back when Hubbard was still writing SF, and I have his first two novels, which I bought when they came out. He also wrote for the pulps, at the going rate of 2 cents a word.
I remember reading a letter to the editor from Hubbard in one of the pulps, announcing that he was quitting the SF writing business, because there wasn't any money in it. In that letter, he said that there was much more money in starting a new religion--which he then proceeded to do.
I'm not sure if I still have the magazine that letter appeared in. I tried to find it a few years back, among a stack of old pulps I had put in the attic, but unfortunately I couldn't locate it. But my memory of his basic point is clear enough. There's more money in starting a religion and milking the suckers than there is in writing SF for 2 cents a word. That's what he said, and that's what he did.
Battlefield Earth was a *terrible* book.
Had it been 1/3 the size, maybe. It had a LOT of satire in it -- it basically was a satirical book.
But it kept ending, then restarting, then ending, then restarting.
What is sad is to imagine how stupid people must be who think L. Ron Hubbard, an average if amusing writer, and a huckster of slightly-above average talent, as a genius for the ages.