It isn't mere dogmatics. Scripture is clear about the cause and nature of original sin.
Re: "torture for nothing"
What do you think a just and loving God should do to unrepentant sinners instead of eternal hell? Honest question.
Discussion
Why is scripture, which was largely tuned by the Catholic Church, in a Bible full of contradictions, any standard at all? Punishing people for eternity for merely not encountering and affirming the right doctrine can hardly be a just and loving act. God created us imperfect according to the Bible. FWIW
Scripture is older than the Roman Church
The bible is full of apparent contradictions that one finds are not actual contradictions with careful study.
There is such a thing as absolute truth and objective moral standards. The Scriptures are the best account for this reality.
Hell is not for deniers of right doctrine but deniers of the lordship of Christ and their need for salvation.
I encourage you to spend a more time studying scripture, if for no other reason than to steelman your opponents.