Well, no reason.
Seriously though...if you're looking for a reason to, or not to do, Public Forum, I've got an answer for you.
If you were selling someone on baseball, what would you say? It's good exercise, trains hand-eye coordination, encourages teamwork, yada yada.
Similar for other sports (builds character!). Similar for other games (develops logic!). Similar for musical instruments (passion for the arts) and languages (start 'em early!).
Ok, here's the selling points for Public Forum (for brevity, we'll stick with top 10):
1. Writing skills
2. Research skills
3. Public speaking skills
4. Teamwork (2-person teams)
5. Reading people (every judge is different!)
6. Develop voice (speaking clearly & quickly)
7. Politeness & decorum (judges don't vote for rude people)
8. Quickly developing broad knowledge of topic (new topic every 1/2 months)
9. Learning to lose with grace
10. High-level English
Yada yada, etc. So, what's the difference between the PF debate and the other activities?
This list is literally the social and hard skills you need to A. get into and B. succeed in top universities, at jobs and in the business world.
Musical appreciation is great. Hand-eye coordination is pretty cool. Ordering dinner in French-- it might spice up your date. But none of these things are cross-applicable to everything that might fly at you in this life (unless that basketball career really takes off).
Take a look at that list again. Which of these wouldn't serve anyone well in college & work?
Now, I promised reasons why not to do Public Forum too. Here goes: why not to debate:
1. You've already mastered these 10 skills
2. You're rich & love the margaritas-on-a-beach life
3. You know your true passion, it makes you money, and it doesn't relate to those 10 Reasons
4. There's only so many hours in a day; you don't have time (it's true; benefits like these don't come without time!)
5. Self-improvement just ain't yo thang
To be fair, these are all 100% legitimate reasons. If they apply to you, I hope this post has saved you from many wasted hours.
If not: welcome to Public Forum, and welcome to debate.