I can't wait to have apps and services crash and burn left and right due to accidentally (or maliciously) created non-UTF8 filenames in world readable directories.
That is hardly the only problem with such a serialization format, although it is one of them.
> I can't wait to have apps and services crash and burn left and right due to accidentally (or maliciously) created non-UTF8 filenames in world readable directories.
It is not only accidentally or maliciously. Sometimes it may also be done deliberately because it is a character set other than Unicode, without the intention to be malicious.
(A user might also deliberately want to display file names using a different character set, perhaps in order to ensure that all characters can be displayed unambiguously. Of course, this is not necessarily what everyone intends, but some people will.)