This Mormon’s reaction to the Jesus/Joseph Smith DVD surprised me to some degree.
At the core of Mormon doctrine are a host of non-negotiable claims: that not only do practically all other Christian sects adhere to an errant theology (the Nicene creed), but their priesthood authority is null and void in its entirety. None of their saving ordinances are efficacious, and none of them are recognized.
I don’t care how much frosting you coat it with, but that’s a very bitter pill and I’m frankly mystified why we expect that other Christian denominations should swallow it with a smile, without fighting back with all the resources at their disposal.
Similarly, to claim that our missionaries aren’t “tearing down” other religions may be true in terms of process, but certainly not end result. The convert has to reject his current beliefs and his current loyalties and his current sacraments, no dual citizenship allowed. Why pretend there’s anything nice about what we’re up to (Matthew 10:34)?
The Mormon church stands as an existential (albeit philosophical) threat to the broader (Nicene) Christian fellowship. We should stop being surprised that this raises some people’s hackles, or that they believe we are as wrong and misguided and apostate as we believe they are.
–Eugene Woodbury
Read more here
LDS & Evangelical Conversations 
The main point of your quote is in the first paragraph. It is because of this that I am always asking, why do the Mormons want so badly to be accepted as main line Christians? And why do so many Christians think that the Mormons have just derailed, and are only in need of some adjustments to get back on track?
Sigh.
As a Mormon, I never wanted to be accepted as a main line Christian. But I wanted my belief in Jesus Christ to be acknowledged.
I think the problem comes in the definition of Christian–I believed in Christ… so why was calling myself a Christian inappropriate?
I WOULD LIKE TO SHARE MY TESTIMONY THAT I KNOW THAT THE LDS CHURCH TEACH THE TRUTH BECAUSE I’M PART OF THAT .I’M THE FRUIT OF MISSIONARY WORK.I LIVE IN URUGUAY.I’M A MEMBER OF THE CHURCH SINCE 1992.I WENT ON A MISSION IN BS.AS,ARGENTINA AND I GOT MARRIED IN THE TEMPLE.I GOT 4 KIDS WHO ARE VERY SPIRITUAL AND DIFFEREN FROM THE OTHERS THANKS TO THE TEACHINGS WE RECEIVE IN THE CHURCH. I FEEL FREE FROM VICES AND WE LIVE VERY HAPPY.I KNOW THAT JESUS IS MY SAVIOUR.AND I THANK TO JOSEPH SMITH BECAUSE HE GAVE HIS LIFE FIGHTING FOR WHAT HE BELIEVED .