Except you can't export multiple files at a time in QuickTime Player. Besides, in iTunes, once you set the Library and Import format, it's one menu command for every batch of files. In QuickTime Player, you have to set every single file destination, file name, and export format for every single file conversion.
I think Adolfo Rozenfeld made an unusual recommendation -- using Compressor. I haven't tried it, but it's certainly an interesting suggestion.