Christians; why get upset at us when we explain why we don’t believe?

Agnostic here.

Every few months we get the “why don’t you believe” question—usually by well meaning people genuinely interested in understanding us better

The question is specifically directed at non Christians.

Yet it seems like every single time the forum turns into a back and fort debate.

Does EVERY discussion online have to turn into an argument? Don’t get me wrong, I know some of those responses are in good faith, people trying to clarify our thought process. And that’s cool. But there’s clearly others who are just itching for a fight.

Why? I understand the importance of evangelism in your religion but do you really think browbeating someone online is going to win anyone to Christ?