Blizzard could have made more money if they kept the Mythic Skins on the BP.
If they would have really thought about it they could have still made the Prism Shop but it could have been Mythic Weapons instead of 1 they could have added 5 at a time but they could have also brought back some rare skins to put in there also with the weapon skins. I’m not saying the rarest of the rare… those can stay locked away. They could have also added in Limited Skins…Ones that they would never bring back again.
Yes you get some Prisms on the BP but the Rare and Limited skins they offer at the time cost more then what u get on the BP which would make those die hard whales that got to have every skins spend that money…
You appease the F2P players but also offer something towards ur swipers.
Yes it will still make some people mad and cry that they are being greedy. But lets face it… that was never a secret. 
But at least this way… you get more options then old Mythic skins and rotating in the newer ones just in case u missed it the first go around.