The fact that the kedoshim in Europe wore light suits and hats of any style shows explicitly that Hashem’s army has no black and white dress code. It is only today where artificial chitzonius is the norm, that such a dress code has evolved, the same as the Borsalino hat. (Is the Borsalino also a part of Hashem’s army’s dress code? What did the Rishonim do before the opening of the Borsalino company? Do the Rishonim have any chelek in Olam Haba?)
It is just a game of appearing yeshivish and wanting to fit in with a certain crowd and in some cases, wanting to feel that one is above the hamon am. There are many sincere yidden who dress many different ways.