echo 'Hi!' | tee "$(printf "foo\nbar\tqu ux.txt")"
cat foo$'\n'bar$'\t'qu' 'ux.txt
...if it was the 1970s. Nowadays we use Python etc for tools where it’s less acceptable for them to fall apart, though everything falls apart at some point, spaces or otherwise.
The maintainer responded by saying, basically, that the behavior was deeply baked in and was not going to change.
Some things across different systems have pitfalls as a result of their implementation, or some features have pitfalls. There are half a dozen things I can point to on windows that are worse than the "spaces in filenames". Hell, windows doesn't even support ISO 8601 dates, or times to be properly placed in files. It restricts symbols much more than Linux / Unix