That is NOT a bug. Microsoft wants you to use NTFS. The cluster size increases as the partition size increases. That makes the use of the storage space less efficient.
The utilities from the drive manufacturers make it easy to prep external drives as you wish.
There are other reasons to use NTFS which I won't get into here. The main reason to use FAT32 on an external drive is for cross platform compatibility. Most users probably don't need that, so they should be using NTFS.