Comment 5 for bug 41828

After consdering the question, I think I agree with you and we should make it work. Unfortunately there are some problems, notably:

https://bugzilla.mozilla.org/show_bug.cgi?id=318093
`Plugin finder service should be more verbose about why manual installs of plugins are needed'

which makes it difficult to tell what's going on. Certainly currently in my test system strace reveals that whatever the problem is, it's probably not a missing plugins directory somewhere and probably not a permissions problem.

Also, note that at the time I'm writing this Mozilla upstream binaries can't manage it either. (https://bugzilla.mozilla.org/show_bug.cgi?id=320396)

I'm discussing this with upstream.