Running outside is the same, at the end of the day you return to the same place you started. The point isn't to get somewhere fast, it's just to run. We do it because we want to be healthy and athletic people. In the same way, you join debate not to get at the truth, but to increase your mental abilities.
You have a good point here - why not just learn to understand and articulate arguments by doing something productive for the world rather than competing against one another in pointless weekend tournaments?
It makes no sense to compare debate to radically different activities (like programming or starting a startup). I'm not arguing that debate was the best thing that anyone can do, rather that it's a worthwhile and not totally bullshit activity. I understand if you don't want to do it (different strokes for different folks) but I gained a lot from it and I think it deserves a certain amount of respect. I would never disparage a tennis player for having wasted his time just because I find it tedious running back and forth. I would respect him and want to learn about tennis from him.
