That's exactly the problem; you might feel great after the Giro and think it's good to capitalize on that, but at the same time you risk doing too much. In 2011 Kruijswijk went on to compete at the NC after Suisse, where his form was already rapidly declining.
Sometimes resting after a GT is better than keeping on building fatigue, and possibly stretching it beyond your limits. Why do you think Nibali, Majka and Uran won't race until late July?
If the start list is correct, Betancur is going to Suisse as well as Kelderman, I fear the worst for the rest of their respective seasons.