And as ever, The Drinker nails it. Peter Dinklage what a complete clown, if ever a man suffered from small-man syndrome. It is he.
Dinklage is a good actor who has been flattered by a brilliant script in game of thrones which seems to have inflated his ego and distorted his perception of reality somewhat. Hes a dwarf. Fundamentally they are not going to feature in many films or TV shows. In the same way, you don't see many 7' tall actors you don't see many dwarfs. Its a pain in the ass to film and limits what you can do so why would you bother if it wasn't important to the story...like lets say Snow White...
Dinklage himself has been in a lot of cruddy roles as well and hes not really in a position to be appointing himself "king of the dwarfs". Unsurprisingly plenty of them are more than happy to be in roles where their primary marketable quality is their stature. Most actors get jobs because of their looks, not because of their overwhelming talent.