The problem with painting ceramic tile is not that you will not be able to remove the paint. The problem is that the paint will not stick well and the paint will peel off on it's own. When the glaze on ceramic tile is fired, it makes a glass-like surface that is very smooth and hard. Paint does not like to stick to something that smooth. It does like to stick to a surface with a little texture. If you could sand all the surface of a tile wall well enough to break through the glaze, you would have no problem with the paint sticking, but this is hard to do and it's also hard to get the curved edges of the tiles.
One of the great advantages of tile is that the smooth, hard surface makes cleaning easy. The surface of paint does not have this benefit.
Paint also allows water vapor to pass through it and tile does not. This means that the water vapor will increase the paint peeling potential and, again, make it less cleanable.
So the total result is that for a kitchen or bathroom situation, you are much better off in the long run to replace tile with tile. For somewhere in a less demanding environment, you can replace tile with drywall and paint that.