The Book of MORMON contains hardly ANY LDS 'doctrine'.
It's a mere fanciful story with some bible stuff tossed in.
Any real DOCTRINE is found in the Doctrines & Covenants
I wonder why they don't give you a copy of THEM and ask you to 'pray about it'?
At a Bible study I attended at Laughlin AFB, TX, in the 70s, I met a retired USAF E-9. He was very learned in his knowledge of the Mormons. It was his opinion, that being as ole Joe Smith was a teller of tall tales. He thought Smith wrote the Book of Mormon, not to start a new religion, but to write a fairytale, with the idea of making money. I don't know, he may be right. None of us are able to get in Smith's head. My opinion is, Smith was a disagreeable person. People may very well have taken his fairytale seriously, and started a new religion, and Joe just went along for the ride. You talk about itching ears, ever learning, but never able to come to the knowledge of the truth.
As far as your other point, I agree. When I left the Catholic Church, those guys never tried to unteach me about all the false doctrines I had. They just concentrated on showing the truth, and the false ideas came out by themselves. My dad told me there were many ways to reach Heaven. That is false, of course. I found out there is only ONE WAY to reach Heaven.