I agree. To be truely critical, you absolutely need to study the doctrine but independent of the dogmatic practice.
I know, seemingly contradictory.
I believe when membership takes a point of doctrine into cultural practice the beliefs can become warped depending on those around you. It is no longer pure doctrine, but a shade of doctrine. However, the culture can have such a dogmatic view of relgion (We're right), they may automatically believe their practice is correct...and it may certainly not be.
I'm talking about these peculiar things that LDS culture deems doctrine, when it really isn't. Like drinking soda with caffine is against the doctrine of the Word of Wisdom health code. Caffine is never mentioned, but the principle taught is to avoid addictive substances. We are specifically counseled against tobacco, alcohol, drugs...but people equate this somehow with Caffine, which most certainly can be addictive.
Some choose not to drink caffine, others choose to drink it in a manner that avoids addiction. However, the majority practice of the Word of Wisdom has resulted in the mainstream belief that Soda with Caffine is against Church Doctrine, and judgements are made against those who do drink those beverages.
There are many such examples of things like this. I could go on and talk about R-rated movies, or Keeping the Sabbath Holy, etc.
That's why its imporant to study the doctrine, over practice.