This is the legendary Rox Dene and she pretty much set the bar for what an "ideal" hunter horse is.
This is a picture of her as an older lady, but she is still beautiful. Your horse is very nicely put together and though I don't know that he would be "ideal" I don't see any flaws that would immediately eliminate him from the hunter ring. I will say that you omitted his head in this picture and that head shape, size, and attractiveness can make a difference in a winning conformation hunter. If the person was making this judgement solely on your horses conformation, then I would say they are rather silly, because your horse looks perfectly suitable to most AA rated horse show hunter rings. But you could be hiding a roman nose, pig eyed, demon horned head, and then they might have a point about your beast. Though conformation plays a big part, it still only counts for 25% of a conformation
hunter's round, with movement, jumping style, stride, and overall round (finding eight good distances, perfect flying changes, all on an ever steady rythym surrounded by an illusion of an effortless easy ride that the judge deems enjoyable). Many horses who show in the hunters do not specialize in the division, and most classes aren't particularly concerned with confomation, but rather how the horse uses what it has. I wouldn't allow one bad opinion deter you from a really fun experience. There are also many different divisions of hunters, some you might find more suitable for your horse than others. Unfortunately even with a very nice hunter and a very nice round, you can be outplaced by one that is considered fancier. In those cases, you simply do your best, and hope the judge is fair about considering talent and a good ride equally. Unfortunately there are those few times where you might feel a judge placed a fancier horse with a bad round over a nice horse with an "ideal" round, but that is why it is a sport based on opinions, and that is when you remember the judge, and kindly refuse to attend a show where they will be in control of the ribbons, or just chalk it up to character building and be a good sport. Most importantly work on your own goals, and don't allow the competetion to deter you.