IP inflames backlash. IP is counter-productive towards its goals and destructive to the solidarity of the party.

We have had 30 years, and the only success IP has had is with gay rights - a topic that costs the 1% nothing financially (which is all they care about) but gives their propagandists more ways to inflame the fundie rubes.

Also, gayness cuts across all "tribes". There are rich gays, poor gays, black gays, white gays, male gays, female gays. Gayness can hide, as it had done for millienia. All those facts mitigate against a racist/sexist kind of backlash, where the "otherness" is out there for all tribalists to see.