Should've thought about that before implementing h264 support in Firefox, back in the days where Mozilla was still a relevant vendor in the browser market. At this point in time, such articles seem hypocritical.
In terms of "put up or shut up" I should make clear I'm not advocating Mozilla shut up, more that they put up next time something like DRM in browsers is on the table (which they ordinarily do, which is why I use their browser).