Most new computers today are sold with between 4 - 6 GB and that is set to rise. Yet most filesystems continue to store their databases on the physical drives be it SSD or Hard Disks. They have very clever caching but yet still more often than not when a file's meta data is queried the drive has to be powered and we have to wait several milliseconds.
Yes, your NTFS database CAN reach up to 1 GB on a really large modern drive with ACL permissions set all over the place, but so what? When you have several GB of memory free kicking around would you not give that up for far more time on your laptop and quicker responses across the board?
And before you say a word about data integrity, we already have transactional filesystems to solve that problem...
PS - Keep in mind *DATA* and the filesystem database are distinctly different things (with larger files the database actually gets smaller)