Interesting point of view. I would challenge this article by asking you what you are using the roadmap for. For me, a roadmap is mostly a communication tool. Off course, if I say I'll do something there's a commitment to that. But I always try to create an understanding that my roadmap is more a vision open to refinement and improvement than a set of solutions.

In this context, I find a feature roadmap easier to share most of the time. Discussing which problem I'm solving is always difficult for many reasons: 1) unless I'm really unfocused, the big problem I'm solving should be the same. I could tackle different parts of the problem, but it is more difficult to communicate 2) when you present a priority between problems you are solving, people develop a "negative" mood. Every problem is a priority. If you focus more on general features, there's more the issue of creating "pet projects".

That said, I always use a problem point of view when working on prioritization and approaching a product.