This is the end........

I think the ending to Angel Earth's "Circle of love.." is just right for what's gone before and that's a fade out.

If that song had had an abrupt ending it would spoil the whole ambience that has been so lovingly created throughout the previous 15 minutes.

I think this is the crux of it. The ending to a track needs to fit in with the rest of it (obviously) and some just don't lend themselves to "in your face" endings.