The answer is they hope people are very stupid indeed.
Everyone who uses multilevel marketing techniques to sell either a product or a way of life must really hate the Internet.
For out there on the internet you will find sites both for and against (for example): Amway, Noni Juice, Nu Skin, Mary Kay, Nature’s Sunshine Products, Herbalife, Nutra-Smart, XanGo, Living Scriptures, 4Life Research, NSA, Pharmanex, Quixtar, Shaklee, Covey, Kirby, Unicity International, USANA Health Sciences, Inc., Mormonism, etc., etc.
Some of the sites are purely bonkers with criticism that is unfair or based on a misunderstanding with someone. Others. however, have very valid and genuine criticism of the firm or organisation concerned.
The Mormon Church, however, is one of the few that actually warn people not toseek out critical information on it! To many people, this is the red rag to the bull. "If you don't want me to find out some information, then there's a reason why." And people use the Internet and discover websites like this one, or Recovery From Mormonism and the like.
Prospects (yes, Mormonism uses American Insurance sales terms for people thinking about joining their church) can see how many women (married and single) Joseph Smith had as 'wives' what the Danites were, which modern LDS leaders thought it better that a young lady allow herself to be murdered rather than raped and other such gems of LDS wisdom.
Many decline to join such a church. Or, if they do, keep their wits about them and bale out as soon as the nutty ways of Mormonism become all too apparent.
And that is why the Mormon Church doesn't want you on the Internet, researching all about the Mormon Church. No salesman wants to lose a prospect, do they?