Everyone has an opinion on the ideal dog. Size considerations are due to breed considerations, what they're designed to do. Commercially available larger sized dogs tend to cater to a market seeking calmer family dogs (King/Shiloh Shepherds), and the quick-footed events working dogs do doesn't gel with a cumbersome build. LC dogs (as of right now) are not something you can take in the AKC ring, although that's hopefully changing. Combine an over-size with an LC and you've pretty much got a pet market.
There are good dogs in every size, every color, every coat length. It works for you and that's all that matters. But folks breeding to a standard have to keep to their standard, and that doesn't include massive oversized dogs or coats (if they're in AKC, at least).