It's a bit deceptive imo to not mention detachability when talking about headphone cables and durability. Same reason people care about about replaceable batteries in phones regardless of how long the stock battery lasts. Plus the T90 cable is very average. Sure it's more durable than HE-500, but it's on the same level as most headphones like M50. Doesn't even have the cloth wrap like the HD700.
If you look to the Original post that I was replying to , he was worried about breaking the cables by accidentally tugging on them, my comment about the build quality was in this context.