I will argue that by many standards, what we view as barbaric has better outcomes. Have you met a Singaporean? I disagree with their criminal justice system (as I do the U.S. but I rank Singapore’s as “worse”) and yet it has better outcomes for the majority of its citizens by most measures. Are they the measures you and I care about? Probably not, because to you and I, hanging someone for using heroin is not a fair price to be paid for a lower crime rate and higher GDP, but that’s a moral judgement, not some objective “modern” absolute. If you don’t value human life above all else (which many cultures don’t) then killing a few drug addicts a year to make life for millions of others better, that’s inconsequential — and excellent “modern” thinking about doing the most good!
If you can’t imagine why the bad of anti-lgbt sentiment is far outweighed by the good of community-spirit from an anti-lgbt religion then you’re not considering “outcomes”.