A spouse can see things from an outside perspective. If your spouse thinks it's a bad idea, then maybe it really is a bad idea.
In the past, I was upset that she wouldn't connect with my vision. After lots of failures, I find that I would much prefer her to be constructively critical of me in this way, rather than always supportive. For one, if she trusted me blindly, then I would have immense guilt when my ideas crash and burn after costing us time and money for no return.