Why does MS-DOS 6.22 boot so slowly?

I'm running MS-DOS 6.22 and other versions of MS-DOS in qemu-system-i386, and I've noticed that MS-DOS 6.22 boots very slowly: several seconds. Why is it, and how can it be fixed?

Some more info:

DOS 6 waits 2 seconds after displaying the “Starting MS-DOS...” message, in order to wait if user presses F5 or F8 keys with or without CTRL modifier.

F5 skips the startup files (CONFIG.SYS and AUTOEXEC.BAT) completely.

F8 asks for every line in the startup files if they should be executed or not.

Using them with CTRL means to skip loading DoubleSpace or DriveSpace before processing the config files.

The delay can be removed by putting SWITCHES=/F in CONFIG.SYS.