Hi revivo2k,
What you are suggesting sounds great, but it is really hard to make the model of "everyone contributes" a reality. There has to be some chain of management for code changes getting applied to a module or the core because what works for some may not work for others.
Now that is not to say that no one should try and contribute fixes and enhancements to the core, but what I have found is that sometimes it is easier to let the extensibility of DotNetNuke work for you. What I mean by this is that you can enhance and create the module and offer it to the public on your own. If your version is better for a majority of users then your "suggestions" will be hard for anyone to overlook. Not only will you have the proof that it can be done the way you suggest, if you have other people seeing your vision they will in turn help you to get your point across.
Case in point is the Wiki module. That project was going nowhere until someone released a much better version as open source.
And to bring it back around, this is also how the current blog module became a DotNetNuke sponsored project (it used to be part of the Forums).
That being said, I don't want to detract from your overall point that the feedback loop is not what it should be. Believe me, I know your frustration there and I don't see it being "fixed" any time soon. But as Sebastian pointed out earlier, having the modules as their own projects is definitely in our favor.
Anyway, just my two cents on the matter.