Feedback is fickle. And precarious.
I asked this question about feedback at Creative Director Camp (Class #002 Bureau of Digital): How far do you let a designer go down a path that you know may not be right?
On the one hand, you stop him or her early. Then they have many more hours of budget to explore other avenues and evaluate before settling on one idea. On the other hand, you do not have their brain. You do not know what experiences might take them down an exploratory path, or what legs this idea might have in the future.
If the box is too tight around your team, they can’t truly explore for themselves. If the box is too broad, they can get lost in the trek.
At some point, “the absence of limitation is the enemy of art.*” And without parameters, the ideas cease to exist in the first place. So revel in the passive furrowed brows and the “I just don’t think it’s going to work.” This only gives your idea more room to grow, and an opportunity for you (and your team) to push your creativity even further.