What is wrong about Google Drive is that they count your email and drive storage in same quota. Few months ago, I exceeded my quota on Drive, and Gmail started giving me warning that I am running out of space, and will stop receiving emails if I do not upgrade, or free-up space.
What is wrong about it? Would you prefer to have 2 GB shared quota, or separate quota of 1 GB each? With shared quota you have more flexibility as to what service you prefer to use more.