The rules for answering say "be sure to answer the question" and although I can't tell you how to fix your problem, I'll use your question "Am I missing something?" to submit this comment:
You're probably not missing something because something broke in Mavericks regarding mounts and I've been waiting and hoping they will fix it. I am NFS mounting a different way but perhaps the problems are related.
I have a longtime NFS mount of a Linux system's user directory onto my iMac using a Directory Utility entry with fields RecordType dsRecTypeStandard:Mounts, VFSLinkDir /Users/tux/linuxHome, VFSType nfs, etc.
This was working fine across 2 previous upgrades of MacOS and abruptly stopped working when I upgraded to Mavericks. I don't know if it's just NFS mounts with Directory Utility or DU mounts in general.