You also cannot easily sort by Type, only Kind, which is not the same.
It's another concept from the classic Mas OS. It didn't support file extensions (as it didn't need them) and uses a file type code to determine which application opens a specific kind of file. OS X added file extension support as it's Unix/NEXTSTEP derived. There's also an additional creator code to indicate which application and version created a particular file, which Mac OS will use if it's available.