Your system, not prescribing any morals, allows for people to believe it is moral to burn whoever they want at the stake for whatever reason, which would be arguably worse, no?

Why do you think humanists burn people at the stake? What a ridiculous thing to say.

You know this is no solution to the problem: one person may like to be treated differently than another, different societies decide what is acceptable or not, the rights aren’t guaranteed by social contract.

And how does a god that I don’t believe in because it’s ridiculous help the situation?

This is your answer for Catholics and Catholicism though, it’s not all Catholics that have done this

Absolutely not. One can be a humanist and a Catholic Christian; they are not exclusive. Rather, the humanism what makes them have an actual moral system instead of just accepting what the church has to say. Again, see genocide and witch burning.

Please stop putting words in my mouth and also assuming that you know things which you have not investigated.