I agree with Cleary that the tuxedos, vests, dress shoes, etc. are pretty ridiculous. The "golf attire" is perfect IMO. I don't think you need to be any more dressed up than that to play a sport. Golf is a much more prestigious sport than pool and they don't require people to dress like waiters. A long sleeve dress shirt, tie, and vest all restrict my movement and I couldn't imagine stretching for a long shot in that and being comfortable. A polo is nice and allows for free range of motion.
Dress shoes are not necessary either. You're on your feet alot in pool and dress shoes are just not comfortable for extended periods of walking/ standing. What's off putting about sneakers? They're designed for performance, they give good traction, and allow for much more than just standing in one position.
I think slacks/ khakis, a polo, and some sneakers are fine. I don't think the color matters, so you don't like loud colors, so what? How are loud colors unprofessional? I personally have polos in almost every color you can imagine and paired with the right pants and shoes I look sharp. I think the examples of Ricky Fowler put off a good, professional image, loud colors and all.
So, like I said, I agree with Cleary that dress codes in pool need to be updated to what I see as more appropriate attire. Some may not agree and that's fine, I can agree to disagree.