All the debates that I have seen are quite formal affairs. There is a proposal, proponents and opponents. They get equal opportunity to make their cases, and then there is a vote.

The ones I've seen are usually polite rather than heated.

You seem to be using the word 'debate' to describe what happens in BS as a consequence of disagreement.

Person A says "I think this". Person B says "You're wrong, its this".
Person A gets miffed by that and a slanging match develops.

In Politics it is not unusual to find two completely opposed sides and arguments are predictable. Some individuals appear to get more impassioned as a result of opposition and then it's down to the usual BS warriors to take their places and the popcorn comes out.