I don't find the values of society pre-1980 to be "vile", as you claim. What I do see is that amongst the good we have created human history is also littered with prejudice and intolerance. Slavery, for example, was pervasive in many cultures for centuries. Women have often been oppressed (and still are - see, Taliban) and denied rights in societies dominated by male values. From a modern Western perspective, we have learned to overcome those values and attitudes. The rejection of the homosexual is another such example. When I was young homosexuality was typically abhorred by mainstream society and even criminalised. In my country it firstly became decriminalised (in the 1980's) and then it was made unlawful to discriminate on the basis of sexuality. Homosexuality is now being accepted as just another feature of the diversity of human behaviour. I have learned to change my own attitudes from homophobic in my youth to tolerance and then acceptance.
There was no "rational" basis for the prejudice against the homosexual; their oppression was simply a feature of human mores that we now see as wrong, in the same way we came to see it as wrong to oppress women (in our societies they only gained the vote a little over a century ago) and wrong to discriminate against people on the account of their race.
History tells us what we have achieved. But it has also shown what we got wrong. I would not look to history to justify prejudice and oppression.
You link the issue to the change in reproductive rights in society. There may be a connection to that, since we no longer accept women are mere vessels to ensure the continuation of a line. Since reproduction has lost its paramountcy the homosexual is therefore no longer a "threat" to those values and no longer seen as "unnatural" (which is ironic since homosexuality occurs in nature). I would say religion has long been a shaper and enforcer of those so-called "traditional" values - and often still is.
Over the centuries our understanding of the universe has changed, from putting us at the centre, on a "flat" earth, to existing as an infinitesmally small rock in the midst of eternity. We have also learned to change how we see ourselves and the acceptance of those who are different amongst us is part of that journey towards understanding. That includes acceptance of the homosexual.
I won't discuss the point you raise about doping as that is entirely another issue.