Those few extra pounds can reduce a dog's life span by 2 years or more, make them more prone to arthritis, diabetes, heart problems, difficulty breathing, just to name a few. Being politically correct and ignoring a ever growing issue may prevent some hurt feelings, but it won't help to educate the public about how to keep their pet at the correct and healthy weight. A dog can't get on a scale and decide to loose some weight, it is the owner who needs to notice and make it happen. Someone has to speak up for those dogs who even it they look happy are not living the best lives they could be.
I see so many over weight pets and so many owners simply refuse to take the fact that their pet is obese seriously. "Oh we love her so much that is why she is fat." "He looks cute a little bit chubby." "Oh I do feed her less, but it isn't working." "Well I just have to give him a treat when he seems so hungry." And on and on and these pets are the ones who suffer the most. I have two recently diagnosed with diabetes and they are both young dogs, the one is totally blind and the other is nearly there. I have a number of dogs 6 or a few years older with sever arthritis because they are fat or huff and puff and pant constantly from the slightest exertion.
So no I don't think we should "be polite" and not point out when someone's dog is a "little" over weight. Kudos to those who care more about the dog and their well being than hurting and owner's feelings.
Yes I feel VERY strongly about this because I see first hand EVERY day dogs that are suffering because their owners don't know or don't care to put a little effort in to feeding them correctly.