Everytime I play on voobly, everyday, I see a lot of games under WK mod, when I told people or ask to use 1.5 GameData, sometimes I got answered there's a special event running under WK mod. but I never see the event. and rarely see players using it, may someone answer me why people dont liek the free mod and go through a hard/paid mod to play with expansions?

You cannot teach an old dog new tricks. We have announced this for months and they wouldn't move to 1.5 Game Data. I guess we will be forced to unrate WK sooner or later, so they finally start playing the HD patch that is available for everyone.