Anet devs, here is one easy way to make people stop hating the company whenever a Festival came up (and might make you look good on your annual review with your supervisor).
Please bring the old achievements back once a year per festival. A lot of us starts after HoT or PoF, and missed all of the good all days.
You can just bring 1 category back per festival, ie Blood and Madness 2013 this October, Blood and Madness 2014 next year October, A Very Merry Wintersday '12 this December and so on.
Heck, even charge us 1000 gems (or 2000 or 3000) to whoever wants to have those achievem