Here’s their reasoning.
There’s been considerable concern raised by colleagues about the Mail’s editorial position on issues such as immigration, LGBT rights, and unemployment.
Ok, sounds plausible, until you remember the mail has always held these views.
We’ve decided that this paper is not compatible with the VT brand and our beliefs. We won’t be stocking the Daily Mail for sale or as a giveaway."
Oh look, the very next sentence gives away the truth. The mail has always been poison, they only care now because the majority are at last acknowledging it and have stopped buying it(sale is the important word). No more than a PR stunt.