It is a little insulting to the Ferrari engineers to say "oh they are idiots why is the nose like that, there won't be enough airflow coming underneath." However I think many of you are missing a vital piece of their nose design philosophy. If you look at the image there is a slight give-away. As you move back from the front of the FW supports along their profile you will notice that they curve in quite a lot. This basically creates a venturi. This venturi forces the air to speed up as it leaves the FW supports. This has the effect of pulling air from the side of the nose (the slot between the front wing supports and the side of the front wing) to under the nose because of the fast moving air caused by the venturi. This means that even though a large mass of air does not flow between the FW supports, they help to pull air in under the nose and send it down around the side of the side-pods along the floor.
2ndly by the airflowing moving inwards from around the nose to under it, it pulls air from in front the front tyre helping to control the effect the tyre has on the airflow.
3rd without the finger, there is much less to cause turbulence on the airflow going under and around the nose,
I am not saying this is the best solution for their car, I am not saying that it is the worst. I am saying that it is the one they went with and I am sure they have a good reason for doing so.