the Nisio treatmeant really seperates the wheat from the chaff when it comes to [bestgirl]fags. They suffer from the classic problem of equating and identifying an Anime Girls Character with her Hairstyle or Colour Palette. He breaks this mold by switching up their hairstyles quite a bit, and most of the time the only radical change possible is to go shorter.
That is why Birdfags are the most patrician fags of this fanbase, they have long since thrown off the shackles of hairstyles, and are able to enjoy Bird any way she appears.
Let them sneer and laugh, hair grows back, but you can't cut off a characters boring attitude.
People also seem to forget that Nadeko always idolized Tsukihi, and her current hairstyle is probably meant to emulate Birds haircuts of the past.