because the image upload is broken sometimes
I've tried many times since I joined late last week and the image upload has never worked as far as I can see, "sometimes" is wishful thinking.
Is it really a "squatting" problem? I suspect that most communities have been created with good intentions, but during this initial phase where each individual instance is still growing it's legitimately hard for potential users to find them even if the default mod seeds them.
For instance, I've created a local interest community, but it's not yet reached any other instance from what I can find in searching on them. It's likely that someone on another instance will start the same one and if that makes its way to other instances then that will be the "winner".
Anyhow, it'll be interesting to see what happens in the coming weeks. I suspect those unused communities will die off naturally without intervention, survival of the fittest will likely be the way the "best" communities of each topic rises to the top.
Edit: Of course, after writing the above I decided to see whether the image uploads worked and for the first time they have! Always the case when you moan about something :D