I am probably going to get flamed for saying this but I think you can go too far with the "validation of feelings" for ever little incident and all this talk about "believe in yourself, you are special" "you are my everything" talk. Of course we want to boost a child who is lacking in confidence, and protect our DC from life's hard knocks. As with most things though, there is a balance to be struck.
Of course, our DC are very special to us, and they should mean the world to us, and their feelings matter to us very much as their parents (or they should) but as other posters have said, what works in the home doesn't necessarily prepare a child for life in the outside world, and parents nowadays seem to expect teachers, and schools, and scout leader to approach their individual child in the same way, when a teacher or a scout leader's priority has to be that everyone in the group gets the same level of attention and everyone is "special".
Of course teachers appreciate every child's individual value and character, and try to adapt their teaching to that as far as possible, but sometimes it is, practically speaking, not possible.
Let's face it, we are all special to our parents (hopefully we are) and are sometimes afforded special privileges at home, but out in the real world, no one is more special than the other person are they? Well they shouldn't be.
Out in the real world, usually in their first job, having been given totally unrealistic expectations from their parents, from TV, from the Internet, about how the world "should" treat them, these DC are then brought down to earth with a bump, and it can be quite a disappointment and quite challenging for some teens to have to learn that very sadly, sometimes the outside world doesn't give a crap about them, except in terms of the work they produce and the effort they put in.
I think it is kinder and much more realistic, to prepare a child by saying "you are very, very special to us" but outside in the world, we all have to get stuck in and consider everyone else around us, because their feelings matter too.
And a lot of living life as a "successful" adult is I'm afraid about delaying gratification and doing a lot of stuff we don't particularly want to do. And in many cases I don't think we are preparing DC well for that. And that's not their fault. With screens in particular, there is no delay of gratification and the reward comes after little to no effort.
It's a question of emphasis and as I said previously, it's about balance.