I don't know about most people, but I have no issues playing in the rain. In fact, usually the course is less busy, and you can get around much quicker. The greens are usually softer and you can be more aggressive on your approach shots. I wear a Footjoy waterproof jacket and rain pants, and carry a couple hats in the event the brim gets saturated and starts to drip. I also have a backup jacket in the car if I am too wet after 9.
This year, I discovered rain gloves. I had never used them before, and wet grips have now become a non issue.
The only downside is that I wear glasses so wiping them off can become a chore. Also, playing in a light rain is no big deal, but if it continues for a couple hours I have found that by 14 or 15 the fairways become much more of a challenge. I went out yesterday in a light rain. I had my pull cart in the car, but they were allowing carts on the course. I played in just over 2 hours. The course is in really good shape, and it absorbed the additional water easily. I made 2 birdies and 2 doubles, and shot 75.