Because they care about their platform, lets take this thing to consider. How if that ICO we promote turn out as a scam project ? how if that ICO stole all your invested money and run away, they help promoting even just as a hosting. So they want to prevent bad thing happend by not even let any ICO get promoted at their platform. But this is only my opinion, you still can see a official ICO medium page though even the bounty campaign related channel at that project being suspended.