Rather than not encouraging focusing and learning fallacies, maybe we are simply saying that they need to also learn to use them appropriately? Fallacies are not just the informal ones that everyone is referencing here in this thread, but also the formal ones which are very much required for logical argument structure. So even in learning about fallacies, there will be opportunities to understand the difference between informal and formal, why they are different, and how that applies to discourse. Knowledge is power; it just needs to be balanced with understanding on how to use and I think a deep dive into fallacies could actually assist in that regard.