There's an approach to responding to questions of Christian tolerance towards LGB people that, on the surface, works great to gauge how serious a given proponent is. I'm talking here about the proponent who says that yes, same-sex sexual acts are a sin, yes gay marriages are wrong, but we have to be a bit gradualist and meet sinful people halfway and we shouldn't criticize them even if they're in a same-sex relationship, or unmarried men and women living together in sexual relationships, etc.
Straightforwardly, it's this: any tolerance extended towards such people must be equivalent to the tolerance extended towards a racist. And I don't mean 'doesn't think they're racist but says things a crazier progressive would interpret through a racism-creating lens', but full-blown 'thinks one race is superior to all the others, or one race is inferior to the others' racism. Awkward racism.
If a person thinks there is no place in the church, or no place in the community, for the racist - but they think that there must be a place for the currently active adulterer or person engaging in same-sex sexual acts, then they're easily written off as inconsistent and insincere. This can be extended to other sins, from out and out misogyny to economic greed to otherwise.
It may sound like I'm laying out a reductio here, a 'this is why we can't be tolerate of these and those people' attempt, but the fact is that's not true. I actually would be entirely on-board with this sort of thing, and I think being consistent about it across the board - being tolerant not just of the currently popular sins, but also the unpopular ones - is the best way to encourage a proper attitude towards all sinners, myself included.