Most of us have plenty of ideas and not enough time to execute most of them. So we're more impressed when someone shows us something cool that's actually usable rather than another article about how someone had a vague idea for a cool thing that's supposed to become practical in another 10 years, but which we doubt will ever actually get produced.

In short, it's a lot easier to come up with an idea when you don't have to actually do the work to make it feasible. See also: "I have an idea, I just need a programmer or two."

yeah, but it makes sense to focus on the bottlenecks.