YABU. And a bit judgey.
My DS is 7.6 and he wears bermuda type shorts, that are just above his knees, with socks that come just above the ankle. He is one of only two children in his class who wear shorts in winter, but he prefers them. He insists he isn't cold on his legs, and I do have trousers for him if he wants them (3 pairs still with the tags on). He never gets ill, and has never had a day off school.
He wears a vest, polo shirt, sweatshirt, coat, hat and gloves and he wears wellies to school. He has three pairs of clean socks in his school bag every day, so he can change them after every playtime if they get wet. He travels to school by car-share. The school is (too) hot inside so if he was layered up in leggings and trousers he would overheat.
Would I let him walk the mile and half to school like this? No, because I know his legs would get too cold.
Would I let him if the snow was over welly-height? No, because I know the school would probably stop him from playing outside.
When we go sledging or building a snowman, he is fully layered up in long joggers and waterproof trousers.
His needs and comfort have been comprehensively considered and provided for.
Neglect? For fucks sake!