Wetline,
I would argue your point that practicing casting is a waste of time. If you happen to have good casting skills, that's great but one should not minimize the importance of casting to others.
Fly fishing is about casting flies, and being able to cast both short and long distances. Those folks who spend a good deal of their time practicing casting, and perfecting their casts, catch far more fish than those who don't. As a FFF certified casting instructor and one who has been practicing this sport for more than 20 years, there still isn't a day that goes by that I'm not learning something about my own casts and/or trying to enhance them just a little more.
Too many folks end up heading to the river in hopes of catching fish when their casting skills need vast improvement and time would be better spent on that endeavor alone. They go the the river, flail, and then walk away frustrated and without catching/hooking fish. I see this all too often when I'm guiding. The time to practice casting is NOT on the river. It will most likely ruin the fishing for yourself, and possibly for others, especially in crowded conditions.
For those that fish for trout exclusively, long casts may not be required, especially if you're nymphing on small streams. A 10-15 foot cast may be all that is required. The tables turn if you're chasing steelhead/salmon or anything in salt water. If you can't cast 70+ feet all day long, you're not in the game. Poor casts which either spook fish and/or don't land a fly properly can't make up for good fly selection.
The best spey casters in the world routinely practice many hours each week. I've watched Andy Murray (House of Hardy) practice his spey casts before giving a casting presentation just to make sure his timing is correct. I've also witnessed Steve Choate(World Spey Casting Champion) practicing his cast on the Kalama on numerous occasions, I'm sure he practices almost every day.
As to the original point of this post, I have a perfect casting pond near where I live in Toledo, Washington. The pond is quite large, probably 15 acres or so. It has boat docks which serve as a casting platform. On my days off from guiding, I spend countless hours improving various pieces of my casts.
The beauty of the pond is that you don't ruin your fly lines as easily, and they let you practice your roll casting. IMHO, roll casts are the most important casts that one can learn. Having the ability to roll cast 70+ feet is a skill that one cannot underestimate the importance of.
Steve Buckner
www.northwestflyfisherman.com