Id blame their shift of focus to consoles and "consoley gameplay" mechanics.
Despite PC piracy I believe both Crysis and Crysis Warhead made a decent profit and both are still marketable even today, the gameplay and graphics still hold up well by todays standards. Indie PC exclusive titles like The Forest and Distance show that developers who scale their games appropriately can create beautiful and profitable games on PC and PC alone. Studios like Crytek were lured into the console sales myth (no piracy, guaranteed success, huge profits) and tried way too hard to pander to the cinematic shooter crowd.
It was painfully obvous when playing Crysis 2 for the first time, not just the gameplay but the whole DX9/DX11 controversy. Their initial fanbase has more or less abandoned them after Crysis 3, at least I have. I'm a fan of the franchise but wont even waste my money on that game.