His "tactics" are the forum's explanation for when he doesn't win every time he is active (although I don't think anyone cites tactics in his Flanders defeat).
Similar to Super Sagan only loosing when other's fail to cooperate...
It is a handy excuse for fans to still applaud his strength when he doesn't win. It's a supposed weakness critics will try to exploit in predictions. So the topic itself self perpetuates in discussions whether it is true or not...
I'm not a fan of his and I think tactics are his weakness - or better, it looks like he doesn't care, sometimes I think that he thinks that road races are boring anyway, and that he will not subject himself to the rules of this game. But it seems to change a bit, and maybe in order to win the yellow jersey he will make an exception anyway...