The extent of Microsoft's love for Linux might be debatable, but the company certainly doesn't like NTFS: they tried to replace it with ReFS in Windows Server 2012, but that never really went anywhere.
Apparently, the NTFS source code is so insanely complicated that maintenance is a problem even within Microsoft. Due to the usual recursive kludgefest of backward compatibility requirements, a greenfield cross-platform replacement would also be more trouble than it's worth.
Upsides for whom? I believe it highly depends on who you ask and what their use cases are. Being able to shrink at all (i.e. XFS cannot) and shrink _ONLINE_ , per-directory files compression, rich ACLs - some sysadmins need those, some not, for average Joe - doesn't matter is it NTFS or something else.
Apparently, the NTFS source code is so insanely complicated that maintenance is a problem even within Microsoft. Due to the usual recursive kludgefest of backward compatibility requirements, a greenfield cross-platform replacement would also be more trouble than it's worth.