Very true.

I would hesitate to be so inclusive in roadmap development. A product roadmap really is a task for product leadership alone. It really needs to reflect deep thought, informed by data. There is a lot of judgment and market experience that goes into a good roadmap.

The most important aspect of a roadmap is not the future feature set: it is the other supporting things that need to happen in parallel, to provide the marketing and partner support that are needed to make the product a success. A good roadmap makes you think: you see that by a certain date, certain features will hit the market, and you can then ask yourself, "Will we have enough momentum to be able to generate the sales we need for the investment to pay off?" I.e., the roadmap is a vision of future events that helps you to think deeply about what you need to do _now_.

But as you say, a roadmap is only a guess. One needs to always be looking at fresh evidence as things unfold.