EMM386 is a device driver which needs to be started very early in the DOS boot process for it to work -- because most of the rest of DOS is then loaded into memory blocks that EMM386 provides.
It's an .EXE file because the command invocation gives some useful data -- but it can't load that way, and if it could it would be useless because then it was too late to load drivers into the memory regions it created.
EMM386 is a device driver which needs to be started very early in the DOS boot process for it to work -- because most of the rest of DOS is then loaded into memory blocks that EMM386 provides.
It's an .EXE file because the command invocation gives some useful data -- but it can't load that way, and if it could it would be useless because then it was too late to load drivers into the memory regions it created.