They're probally either shy, no topic to talk or to lazy to post. So they just chat in discord or skype and play ingame and helps with wars like Winter.
(Currently watching Hearthstone European Tour Winter Playoff rn)
There is a lot of cool tb players but Xioi is hands down my favorite.
One of the most chill dudes out there as well as one of the best replaymakers, too bad he isnt as active nowadays