Yes.
But today’s Mormons seem to minimize what they owe to Smith.
Yes & No.
Yes, Mormons will often throw Smith under the bus when it comes to having to face much of what he taught.
But, no, in that Mormons realize, no Smith, no Mormonism. Hence, the "larger-than-life" sculptured images of Smith or almost-perfect artistic drawings of Smith that don't match reality [cue Elsie with many of his posted images]. Or the "Praise to the Man" ode-to-Joe hymn in their hymnal.
Hence, the portrayal of him is so often in truly mythical proportion.
[This is also why we've seen the "Joseph Smith nativity scene" posted on so many FR threads. Jesus Christ has a tough time competing with Smith @ Christmas time...as Smith was born Dec. 23...and for so many years -- and is still true today...Smith outdoes Jesus for mentions by Mormons in their testimony meetin's]
Ah, the hubris of Smith has been swallowed by his disciples: "All hell, boil over! Ye burning mountains, roll down your lava! for I will come out on the top at last. I have more to boast of than ever any man had. I am the only man that has ever been able to keep a whole church together since the days of Adam. A large majority of the whole have stood by me. Neither Paul, John, Peter, NOR JESUS ever did it. I boast that NO MAN ever did such a work as I. The followers of Jesus ran away from Him; but the Latter-day Saints never ran away from me yet . . . " (History of the Church, vol. 6, p. 408-409).
Utter Blasphemy! And yet Mitt Romney, Jon Huntsman, and all Mormons follow a man who would utter such a thing!
Does their blasphemy & idolatry know of any bounds?
They can depend on the lack of historical curiosity of the American public. In the 1880s, the Government came close to shutting down the Church in Utah. But who wonders why? No just because of polygamy, but because of the political power of the Church.
Historically, that's not a correct statement. Nine sects split from the Church of Jesus Christ of Latter Day Saints (originally called the Church of Christ, and also the Church of the Latter Day Saints) before Joseph Smith, Jr.'s death in 1844. At least one, the True Church of Jesus Christ of Latter Day Saints, split off during Smith's lifetime because it didn't believe in the practice of plural marriage.
Belief in Joseph Smith, Jr. as 'restoring' a One True Church also didn't keep the whole church together after his death. From the Church of Jesus Christ of Latter Day Saints, we now have the following Latter Day Saints denominations (most of which can be traced initially to (a) groups rejecting plural marriage when it was practiced under Smith, Jr. or Brigham Young; (b) disagreement over the successor Prophet to Smith, Jr.; (c) or groups believing in the continuation of plural marriage after the 1890 Manifesto, or after the 1890 Manifesto began to be enforced under the 1904 "Second Manifesto"):
The Corporation of the President of the Church of Jesus Christ of Latter Day Saints
Short Creek Community
Latter Day Church of Christ
Apostolic United Brethren
Fundamentalist Church of Jesus Christ of Latter-Day Saints
Church of the Firstborn of the Fulness [sic] of Times
Church of the Lamb of God
Church of the New Covenant in Christ
Confederate Nations of Israel
Righteous Branch of the Church of Jesus Christ of Latter-day Saints
School of the Prophets
Centennial Park
Church of Jesus Christ of Latter-day Saints and the Kingdom of God
True and Living Church of Jesus Christ of Saints of the Last Days
The Church of the Firstborn and the General Assembly of Heaven
Blackmore/Bountiful Community
Restoration Church of Jesus Christ
Order of Enoch
Aaronic Order
Zion's Order, Inc.
Perfected Church of Jesus Christ of Immaculate Latter-day Saints
Church of Jesus Christ (Bullaite)
Community of Christ
Church of Jesus Christ (Toneyite)
Independent RLDS / Restoration Branches
Church of Jesus Christ Restored 1830
Church of Christ (Lion of God Ministry/Clarkite)
Church of Jesus Christ (Zion's Branch)
Restoration Church of Jesus Christ of Latter Day Saints
Remnant Church of Jesus Christ of Latter Day Saints
Church of Christ (Temple Lot) (Hedrickite)
Church of Christ (Fettingite) (Hedrickite)
Church of Christ at Halley's Bluff (Hedrickite)
Church of Christ (Restored) (Hedrickite)
Church of Christ "With the Elijah Message" (Hedrickite)
Church of Christ (Hancock) (Hedrickite)
Church of Christ (Burtite) (Hendrickite)
Church of Israel (Hendrickite)
Church of Christ with the Elijah Message (The Assured Way of the Lord) (Hendrickite)
The Church of Jesus Christ (Bickertonite)
Church of Jesus Christ (Cutlerite)
True Church of Jesus Christ (Cutlerite)
Restored Church of Jesus Christ (Cutlerite)
Church of Jesus Christ of Latter Day Saints (Strangite)
Holy Church of Jesus Christ (Strangite)
Church of Jesus Christ (Drewite) (Strangite)
True Church of Jesus Christ Restored (Strangite)
Pentecostal Church of Jesus Christ of Latter-day Saints (Whitmerite)
And the following LDS denominations that are now defunct:
Pure Church of Christ (Clarkite)
Independent Church (Hotonite)
Church of Christ (Boothite)
Church of Christ (Parrishite)
Alston Church
Church of Christ (Chubbyite)
Church of Jesus Christ, the Bride, the Lamb’s Wife
Church of Christ (Pageite)
True Church of Jesus Christ of Latter Day Saints
The Church of Zion (Godbeite)
United Order Family of Christ
Church of the Potter Christ
Church of the Firstborn (Morrisite)
Church of Jesus Christ of Latter Day Saints (Gibsonite)
Church of Jesus Christ of Saints of the Most High
Church of the Christian Brotherhood
Church of Jesus Christ of the Children of Zion (Rigdonite)
Reorganized Church of Jesus Christ (Bickertonite)
Primative Church of Jesus Christ (Bickertonite)
Church of Christ (Aaron Smith)
Church of the Messiah (Adamsite)
Church of Christ (Wrightite)
Church of Christ (Whitmerite)
Church of Christ (Brewsterite)
The Bride, the Lamb’s Wife
Congregation of Jehovah’s Presbytery of Zion
Church of Jesus Christ of Latter Day Saints (Gladdenite)
Independent Latter Day Saints of Nigeria
Independent Latter Day Saints of Ghana
Apostolic Divine Church of Ghana
Just factually - as a historical basis - I'm not certain that would be considered as holding a whole church together.