I think we all agree that there's lift only when the pressure on the bottom of the surface is greater than that on the top. Since this is so, it is wrong to attribute lift to the bottom only (or, for that matter, to the top only). That would be like arguing about which blade of the scissors does the cutting. The "sucking" one gets from a vacuum (complete or partial) and the "pressure" that causes something to move toward a vacuum are the same phenomenon, described differently, not two separate things. When you drink a milkshake through a straw, it's air pressure that pushes the shake up the straw when you reduce the pressure inside the straw. Most people would say you've sucked the shake up the straw; nothing wrong with that.

To those who seem to think the shape of the top irrelevant: consider slats. They increase lift (by increasing the speed of the air over the top of the wing) without in any way changing the shape of the bottom of the wing.