Any thoughts about why Matchbook does not take any of the "convenient" ways to fund deposits like ** or **?

I ask because I often wonder the logic of flying in the face of creating markets as liquid possible by making it as easy to deposit as possible. Is it strictly a cost thing for them, ie too expensive to take these deposits? Or is it something else?

Just curious why almost every other book out there takes these deposits, and MB doesnt. Is there something other than the obvious (cost)?