I'm pretty sure most of the print media out there do exactly what you're doing - performing one or more interviews about particular topic. The good ones though take that material and turn it into an article that attempts to make a point using the information gained from the interviews as support.

There isn't anything wrong with what Mixergy is doing per se, it's just that there on the internet, I normally prefer the article format that can be skimmed first to determine my level of interest.

When something is written, you present the content and then ask for the readers time. With video, you demand the time and then present the content. Since my time - especially on the net - is precious, I'm rarely inclined to give it to you for free.