I must say I find the response of the maintainer here totally unacceptable. This bug should be marked release-critical not wishlist. The bug-fix should be released to the ubuntu security distributions. What is the point of protecting your system from outside attacks when the system itself will attack you?
What is the point of screwing around changing priorities and importance here on launchpad, when you could easily fix the script in 30 seconds?
I don't know anything else about Mr. Remnant, if he is just having a bad day, or whether he is generally a bad maintainer.
Being a maintainer does not give you the right to be a BOFH - you have a duty to do a good job and respect valid bug reports. As this fault caused extreme destruction to the system of at least one user, you should consider it an extremely serious bug. I do not recall a more serious bug report. I don't care that much if X won't start once in a while, but I care a whole lot if my whole system gets erased when I run a program without arguments.
This is an init script that any sysadmin might run, expecting it to do something normal. It is not okay for it to trash the filesystem. Even the infamously dangerous "rm" and "rsync" commands do not trash your entire filesystem when run without arguments.
If Canonical had an email address to "complain about a maintainer", I would be complaining right now. (and will do so if I find out about such an address in future).