schmitzgirly94, I will post pictures of our old Newf that we had to shave down. It did help her keep cooler in the summer, she hated being groomed so it was more humane for her to be shaved down. It also helped her live a longer life.
The outer coat can help protect them from the sun....but, in some cases it's more beneficial to be shaved down.
The reasons for shaving/or education on brushing are:
Owners buying a breed and the dog grows more coat than expected...
The owner is not brushing properly, either show owner how to brush, or if the owner cannot keep up and asks the dog be shaved then we will do that for them...of course warning them of what the coat may turn out to look like. For us it's a case of humanity before vaniety...if it's going to benefit the dog being shave then so be it...and an ungroomed double coated breed is not going to be healthy, comfortable or happy....and will actually cause the dog to overheat.
A double coated dog that is not properly groomed is more a health issue than shaving a dog. I can't tell you how many double coated dogs that were not properly looked after developed hot spots, which turned into breeding grounds for flies...and develop maggots.
As mentioned the only problem is that most times the coat does not grow in properly..the under coat grows faster giving a fuzzy look..plus after wards the coat is harder to care for.
Alot of working dogs with double coats get shaved as well. From what I have seen first hand in my 40 years...I have not yet seen a double coated breed suffer from being shaved, on the contrary they seem to thrive as they don't have all that coat.