Nobody is suggesting that things are bad because they're old. They're saying that HFS+ model older design practices that aren't relevant for modern file system designs and expectations. And what's more, you're kind of disproving your point with those examples:

* FAT32 is frequently criticised for being crap and the FAT32 variants that fix many of it's short comings are often stuck behind Ms patents. In short, FAT32 is a terrible file system that needs to die more urgently than HFS+.

* ext2 isn't really used for anything other than a direct replacement for FAT32. It's not really a practical fs for modern systems and shouldn't really be used on one.

* NTFS isn't a static file system. It's like saying ext is decades old when ext4 is practically a whole other file system to ext2 (while still offering some degree of backwards compatibility). NTFS is similar in the way how it has incremental versions. However even then, NTFS does still have it's critics and, as you mentioned yourself, MS have tried to replace it on a few occasions.

XFS is really the only example you've come up with that works in your context. It's also one of the few file systems I don't have any personal experience with so I couldn't answer how it's managed to keep up with the pace of technology.