The SGF generated when downloading is very strange. It generates a variation for every move made. In particular this messes with “go to end of game” features of sgf libraries/programs. Unless there is a particular reason I don’t see, I would consider this a bug - at least a misrepresentation of the intention: this is the main (linear) game line, and it adds unnecessary bloat (see last line of every file - it is cluttered with closing parentheses).
This issue has been raised before. See the relevant discussion here:
Technically, it does not violate the SGF standard, but it adds a lot of needless parentheses, and I fully support addressing this issues, as you suggest.
Interesting that you report that this causes issues with some other SGF programs. Which in particular?