this is what i do as well, after seeing someone do it. much easier, imho. additionally, there can sometimes be a bit of mold around the top of the cork or under the foil. i've found that if you cut the foil, it makes for more difficult clean-up of this sediment, whereas if you remove the foil in its entirety, you can clean it up easily. and before you ask, no, these wines aren't corked. i'd imagine that for presentation and aestetic purposes, people choose to leave the foil on.