You can have unshod/bf horses living out full time in a sand turnout area and their hooves wont wear away to bloody nubs. I had to use my sand school as a turnout area once for flipping months (the horses were in it 24/7) and I promise you that their hooves were in fantastic condition at the end of this time.
I also hack for miles and I still can't get to the point where they self trim.
was aimed at my horses, who despite my best efforts to get them to the point where they self trim, just grow more hoof, faster. 
The 'hooves wearing' comments are the ones that drive me the most nuts.
My TB's are all barefoot, they are worked in my sand school, on my walker which has a concrete base and hack out across all sorts of terrain inc 1 mile road work, sand tracks, grass, stoney rocky sections and heather tracks. This week one has done 2x 2hr hacks, 3 x 40 min in the walker and 4 x schooling sessions in the sand school of at least 45 min but usually 1hr. This is a pretty average week for him and has been his routine for the last year. His feet grow so quickly that he still has to have a rasp around them every 2 weeks. I have another 2 who also work 5 days a week on average though one does more hacking and one does more school work.
The stimulation from working on different surfaces makes hooves grow. Yes some horses are in the wrong situation or fed a diet that doesn't aid the hoof as well as it could. Not everyone can give their horse a lifestyle that suits barefoot, some horses have metabolic issues that mean it's not possible and some people are just so used to shoeing they cant see beyond the end of their own noses and aren't willing to actually look and learn just for the sake of gaining knowledge just incase it comes in handy one day.
As for the pro situation, I think things are changing slightly. There are a few dressage riders who actively keep their horses b/f to aid soundness and movement - Emma Hindle and Lucinda McAlpine immediately spring to mind - and there have been a couple of b/f racehorses win recently. On the whole however shoes aid consistency and that's something the pro's need when they have so much more on the line.
I do think that over the next few years we will see more amateur riders competing barefoot, some through choice and some, like me, because they used to shoe and it made their horses lame/had a negative impact and thus they have had to make changes.
I'm also really interested in the 'support' and 'protection' comments. Again without starting an argument I'd love it if the shod folk would just explain what they mean. I thought my horses feet were 'protected' by shoes for a long, long time, I had no idea they could and should take weight on the sole/frog.
Having now taken shoes off 4 TB's I'm amazed at what the hoof can do given time and the right situation - I wish everyone could have seen it too, I think then folk would be better able to make decisions over hoof care.
Personally it's of no odds to me if someones horse is shod, but I see so many horrifically shod horses when I'm out and about, IMO it's time owners educated themselves in what a good hoof should look like and how it functions, whether shod or not. I didn't and I ended up with my 'best' mare being diagnosed with navicular. Please learn from my mistake and don't make it yourself.....
And don't start me on the 'typical TB feet' thing....
