Oh wow, that was sneaky. In my experience, all sides do come up with "great ideas" all the time, but it is their job to estimate effort and ROI before starting

Oh wow, that was sneaky. In my experience, all sides do come up with "great ideas" all the time, but it is their job to estimate effort and ROI before starting on any one idea. Sure, there are plenty of engineers who are unable to come up with an incremental approach for a "great idea", but there are as many PMs who are unable to understand the incremental approach and would rather have it all or nothing. Every one of them needs to experience true incremental delivery of value to really buy into it.