The church is more like a hospital to help people get better than a sanctuary for the holy. Just because hospitals have lots of sick people doesn't mean they're ineffective.
Here's an analogy to demonstrate why it does mean it's ineffective.
There are two hospitals in a particular city, hospital X and hospital Y. Both hospitals pull from the same population, and have the same number of patients, and similar ailments. The only difference between hospital X and hospital Y is that hospital X claims to have concocted a treatment that will cure these ailments and produce overall good health, as well as heightened intelligence. Let's call it "treatment Holy Ghost". Hospital Y makes no such claim, and just uses normal medical care.
So if the patients in hospital X actually do not demonstrate a superior cure rate, better overall health, and heightened intelligence as compared to the patients in hospital Y, is it not fair to say that the "treatment Holy Ghost" is ineffective?
Mormons can't have this both ways, although they consistently try to. Either the constant companionship of the HG makes a difference or it does not. If it doesn't make a difference, then, no, we can't judge the church by the members, and it's a hospital like any other. If the constant companionship of the HG makes a difference, then we can judge the church by its members, and its members ought to demonstrate superior moral and even intellectual behavior.
Conclusion: the constant companionship of the HG makes no difference. Any benefits of belief in Mormonism can also be obtained from membership with any other social organization.