[I've read, among others, other questions on this, don't believe this is a duplicate]
I (think I) understand the evidence that distant galaxies are moving away from us faster than closer galaxies. What I don't understand is why this even calls for an explanation..
Take a naive picture, where the big bang was an explosion of matter within space. Matter began spreading with some distribution of velocities, in all directions. Now we observe the universe billions of years later - it seems only natural that the galaxies who traveled the furthest during this time are exactly those with largest initial velocities.
Isn't the same true if we consider the big bang to be a dilation of space itself? The parts of space that 'are dilating' the most (not only them, but the entire portion of space between them and us), must be those that accumulated the most distance from us in the time since the bang.
This naive interpretation doesn't call for 'acceleration' of any kind. What am I missing?