Ekiga 2.0 Released
I'd say the reason that this is an issue is because every project wants to be a brand to itself. Projects don't feel it is enough to be 'the conferencing bit for Gnome' they want to make a name in their own right - and in order to do that they need to have a name that does all the things you list.
Now in one way this is more than fair enough! They put the work in (usually unpaid), they are justifiably proud of the work that they have done and they would like some recognition for what they have done.
But does it help the 'community'? I'd say not really - it dilutes the 'brand recognition' of the open source movement, linux and Gnome by increasing the number of different brands that people have to recognise.
What was wrong with trying to increase the brand awareness of 'Gnome'?
Macromedia, Microsoft, IBM, even RedHat all produce a number of different products but they don't seem to feel the need to give a special name to every product - instead each product reinforces the brand awareness of the company or range as a whole.