I am trying to think of a reason, but the best I can come up with is: "From where I live, Snowdonia is nearer than the Lake District, so Snowdonia is where I went when I wanted to run up big mountains."
My first Category A race was Ben Lomond, and my second was Goat Fell, and I always retained a fondness for races which simply go up and down one big hill (except for Ben Nevis). But somehow I have never made it to the Scafell Pike race.