You know, we did have a poll on whether it should be removed from rotation a while back.
Seems pretty clear cut to me.
But this isn't a problem with other maps of the same size because...
And due to the two ore silos, that hardly matters. I remember a game where the Allied OT was being constantly wrecked and everyone could still afford hordes of longbows. It's less a question of size and more how far the ore fields are from base (but again, two ore silos makes that less relevant). Ridge War's Allied ore field is within kissing distance of the refinery, that doesn't make it a tiny map.
You're thinking of the wrong map, but I hope you can model, texture and rig the ghost medieval soldiers then.
I can think of more convincing reasons why rain might be a problem (like slowdown) and the "psychological effect" doesn't seem to be an issue with the 5 other rainy maps.
I've always wondered what the deal with that was myself, let's let the mapper answer that.