What makes Mormons immune from the incorrect traditions of their fathers? Every single early saint was a convert, and converts almost universally struggle to let go fully of the incorrect traditions of their upbringing. So do members who are "born in the covenant" (since all of us carry our own individual perceptions, many of which are not Truth), so why would the early Church be immune from it?
Personally, I believe one of the most important aspects of the first 100-150 years (at least) of the Church's existence was its evolution away from its roots in apostate Protestantism - the pruning of the incorrect traditions (the bitter fruit mentioned explicitly in Jacob's allegory of the olive tree) of their and our fathers. That growth might be mostly complete by now - and it might not. The attendant changes don't bother me a bit, because I can't envision any other pattern that I like - and certainly not a scriptural one.
That's the biggest reason I am unfazed by ever evolving policies and even doctrinal understandings - that I see such change as inevitable, desirable and even necessary as we strive to see through our glasses, a little less darkly than occurred in our collective and individual pasts.