The definition of 'container' is so massively overridden these days the term hardly has meaning.
Taking a step back I hardly think that this download page (or any similar download page anywhere at eclipse) is going to make but a very small handful of people find a download they are not already looking for. Jetty users have figured out how to download Jetty for two decades now so being featured on the page or not is unlikely to be a revelation to someone that they can download it. I suspect the same is true of every other component within Eclipse, people find them because they know they exist and simply search for it through any engine and get the appropriate hit. So this is unlikely to draw very many new people into the projects, unless I am hugely out of touch with the way the world works. :)
With that in mind, this page is more of a showcase that Eclipse can point to and say 'Look at what we got as a foundation!'. This is a nobel and worthy goal in my opinion and Eclipse is right to capitalize on it....and as a showcase it makes good sense to me that they feature all of the projects that fit the litmus test they decide. I do think limiting it to a small handful defeats the overall purpose though and I think a scrolling slider or bit of _javascript_ that cycles through things would be useful. Emphasize it as a showcase of Eclipse excellence as opposed to landing page to then drill down into for project downloads.
cheers,
Jesse