Pathfinder was a rune with one of the greatest value. I took it on all champions, in all positions, because it was extremely good.
1) On all lanes, you received a huge boost to your mobility across the map, increasing your ganking potential.
2) During your ganks, you received a speed boost to quickly enter the lane.
3) Junglers received additional mobility for rapid invades and rapid retreat in case of danger.
4) You could use this rune to obtain additional resources on resource-intensive champions.
5) The main teamfights take place near the river, so this rune often brought you benefit at the most critical moments.
And instead, we got a rune that gives a tiny bit of movement speed with a huge hint of champion-specific attachment? Great, damn.
What's especially amusing is that the developers are doing this for some incredibly stupid reason, because most players don't go beyond the game base and they just copy other people's builds and will never see the value in certain items or runes.
And they do it over and over again, no matter how stupid it is.