So is Mer^2, so is the MeeGo implementation for N900. Simply put, the community in all of its goodness does a lot of big, huge projects that are years later a work in progress.

Mer? Dead.

Mer^2? Dead.

MeeGo for N900? Might as well be dead.

NITDroid? No movement in a while that warrants full replacement of the current OS.

OS2007HE? It was slow.

OS2008HE? It was even slower.

Besides applications, the OS support from the community - Community SSU excepted - just plain sucks for the last 3+ years.