In word, when you open the program, and click on file/open, the option in the bottom can be set to *.* all filles, and when you exit, it will keep that option the next time you open word.
Excel does not seem to keep that option. It defaults back to all kinds of excel files. Is there any way to keep th option *.* all files in Excel like you can in Word?
Excel can open other types but is usually more specific.
This may be why it does it that way, but my guess is it's just because Office was written by more people than I have in my hometown over a period of several years and we shouldn't expect it to make sense.