Debates are usually dumb performances done for the sake of convincing the audience using as many rhetorical tricks as possible to make themselves look like winners and that therefore their idea has won in the marketplace of ideas. A better system would have the two scientists discuss privately and then come forward with a joint statement either reconciling their views, or stating they are unreconcilable

This is a debate in the broad sense of scientific debate. Both parties wrote their own piece separately (without knowledge of what the other was saying) and submitted them. They have now been published and both parties will now be able to respond to what the other party has said in their initial piece, and the process will possibly continue from there for more rounds. So it's similar to the 'to and fro' of scientific debate in published papers.