In addition to blasphemy against the Holy Ghost, murder is also a grievous sin, and its penalty is the denial of the gift of eternal life. It is God who gives the gift, and God can say who receives the gift and who does not. The Apostle John wrote "Ye know that no murderer hath eternal life abiding in him (1 Jn. 3:15)." The Lord made his point even more clear in latter-day revelation: "Thou shall not kill; and he that kills shall not have forgiveness in this world, nor the world to come... he that killeth shall die" (D & C 42:18-19). He shall die to things pertaining to eternal life.
In the standard works, the Lord reveals that murderers will have a kingdom, for the Telestial kingdom is reserved for murderers and adulterers, whoremongers, liars, sorcerers, and whosoever loves and makes a lie (Rev. 22:15, D & C 76:103).
In the light of these passages, it is clear that it is not Latter-day Saints who limit the effect of the blood of the Lamb, but Jesus Christ himself.
Non-LDS Christians also limit the atonement of Jesus Christ to only those who confess Christ as their Savior. According to their doctrine, Christ's atonement is of no effect to those who do not accept Jesus Christ as their Savior. Latter-day Saints hold a broader view--they teach that his death and resurrection enable all to be resurrected, the just and the unjust alike (John 5:28-29). That does not mean, however, that all are forgiven and are entitled to entry into the highest of the degrees of glory, the Celestial kingdom.