Times have changed.
What you are trying to avoid saying is: Human morals have improved.
Without any guidance from God or the bible, human society has realized:
- That slavery is wrong.
- That woman are not property, and should be treated as equals.
- That adults having sex with minors is abhorrent.
- That racism is wrong. (The OT was very racist, the NT slightly better..)
Granted, there are still individuals who still grapple with or reject these concepts - But what will we realize tomorrow? What will be obvious and accepted by the majority tomorrow that we all still grapple with today? Where will the line finally be set regarding homosexuality? Abortion? Torture? Our society has progressed to the point that we are drawing moral lines over the appropriate treatment of animals... while the OT spent chapters dealing on how best to kill them for God's pleasure.
The WT claims that God's standards are set high and are constant, while society's standards plummet - but the reality contrdicts that. Compared to God's nation of Israel we have it great. We don't worry that a random accusation will end with us being stoned to death in the streets (stoning is a slow and deliberately painful death - a form of torture). We still have a long way to go - but thanks to the enlightenment, modern philosophies, open debate, and modern science - we are progressing forward.
God's standards in the Old Testament fall well short of the standards we've set for ourselves, and already the New Testament is showing it's age and inadequacies as a moral guide as well. So yes - we can look at what was written in the OT and say it is 'disgusting'. It falls well short of what we - through our suffering - have determined "good moral guidance' to be. And next week, the same will be said of the NT.