0. This idea is bad.
1. This idea is probably bad, but if someone wants to put together a more compelling argument we will discuss it at a future meeting.
2. This idea needs to be more fully developed before we can decide whether it is good or bad.
3. This idea is probably good, but it will remain in backlog limbo until someone makes a compelling argument that it is a priority.
4. This idea is good, and while it is not a high-enough priority to displace our current tasks, we will actively discuss including it when we plan our next sprint/release.
Depending on who you work with these may need to be gussied up with manager-speak to let people save face or to prevent people from hijacking the agenda to turn the meeting into a brainstorming session. But treating all of them as synonymous with "no" loses useful nuance.