The problem with determining who's a Christian and who isn't is that defining "Christian" is such a wide-open game.
Is a Christian simply someone who accepts Jesus Christ as their savior and who accepts his teachings as found in the Bible, or is a Christian required to believe a bunch of other things as well?
The biggest sticking point, it seems to me, has not so much to do with Christ, but with Joseph Smith's views on God the Father: the idea that God might have a physical body just drives most non-LDS Christians into a frenzy. Yet, they really have no explanation as to why God, a spirit being (in their view), would bother Himself with the apparent necessity of creating a physical universe. If we all end up as spirits (which at least some non-LDS Christians seem to believe is the case, despite the Bible's emphasis on a physical resurrection), why would God have to bother with this crude, corruptible matter at all? Couldn't an all-knowing God find some way to accomplish whatever it is mortality is supposed to accomplish without having to get "down in the dirt", so to speak? The LDS have an answer to that, but the non-LDS just can't accept it. They want to believe in an all-powerful God, but somehow they can't imagine God retaining his omnipotence as a physical being. The LDS accept Paul's teachings about post-resurrection bodies being raised in incorruption, which is what we LDS usually term as a "glorified and perfected" body.
If one is going to believe in an all-knowing, all-powerful Being who is responsible for creating the entire universe (rational minds might consider this to be quite a stretch of the imagination as it is) and who focuses what would seem to be an inordinate amount of attention on the people who inhabit this little speck of dust that orbits one star out of the "billions and billions" (thank you, Carl Sagan) of stars that He supposedly created, how much more of a stretch is it to imagine that this Being might have a physical body?
You might even look at it this way: sure, any incorporeal Being who occupies the immensity of space could create a universe and populate it with creatures that He wants to eventually turn into angels, who would spend the rest of eternity dancing around His throne (why an incoporeal Being would be interesting in occupying a throne is a little hard to comprehend, but I digress), but to imagine a physical being who created everything in the universe, and who wants to exalt the lowly creatures who inhabit His planets and bring them up to His level of ability and knowledge, well, now, that is what I would call a truly all-powerful Being.
But "Christians" call that heresy. Go figure.