I haven't read Rob Bell's book, Love Wins. But from his video ad, interviews with him -- including a lengthy interview in Relevant -- and a number of critical reviews of the book, I'm getting the impression that Bell has a hard time talking about judgment.
"In the Scripture, over and over again, is the hope and the longing and the assumption that God will fully restore and renew this world, and that will involve a decisive act of judgment or acts of judgments, where certain things are banished," Bell said in Relevant. "And even the picture at the end of Revelation of a new heaven and a new earth, it says there are those who continue to want to murder or deceive, etc., and they aren't in the new city. 'You can't do that here.'"
"You can't do that here" sounds like something a preschool teacher would tell toddlers fighting over a toy. And if people are not allowed to live in the new city, then where are they? In a sort of eternal "time out" until they "choose" heaven? You can't banish certain behaviors without banishing the people who engage in them.
And if "God's love will eventually melt hearts" as Bell claims, then what are we to do with verses such as Rev. 6:9-11, in which persecuted Christians "cried out with a large voice, 'O Sovereign Lord, holy and true, how long before you will judge and avenge our blood on those who dwell on the earth?" Those who were killed for their faith appear to be far more interested in God's judgment -- that is, justice -- than they do about melting the hearts of those who tortured them to death. Or perhaps they realize, as Bell apparently does not, that God will judge them based on the choices they made on earth -- no "do overs" later on. And God makes it clear that this is exactly what he intends to do. He doesn't criticize the saints for wanting Him to avenge them; He merely tells them to "rest a little longer."
We also have this story in Luke 16:19-31, which not only describes the reality of Hell, but also makes terrifyingly clear that we are judged by what we do on earth -- and we don't get a second chance later on. We "choose" Heaven or Hell (that is, we accept Christ's sacrifice on our behalf and obey Him, or we don't) in our lifetimes. After we die, we get what we deserve: Game over. (An adolescent term, yes, but then, Bell appears to be rather an adolescent thinker).
Two articles I want to recommend for readers on this subject: this review and this piece, which reminds us that "Not many of you should presume to be teachers, my brothers, because you know that we who teach will be judged more strictly" (James 3:1). Rob Bell would do well to keep that in mind.
A final point: It is not "mean and nasty" (Bell's words) to condemn heretical teachings in a voice all will hear. If you see someone attempting to escape a house fire, and a bystander is shouting at him to escape over the roof, and you can see (as the bystander does not) that the roof is about to collapse, it's not wrong to loudly direct him to the only escape route he CAN safely escape through. Souls are at stake here, and critics are right to say so, loudly and clearly.