This is related to this post, written by James.
Asana is presented as a project management tool (not just a bug or request tracker tool).
As a project management tool doesn't only lacks some sort of chart and calendar view, but the support doesn't even consider to implement it.
Someone asked for it in January 2012.
They basically answered "we won't add this, forget it!" in June 2012 and despite many other people asked for the same thing, adding their "+1" and their motivation of why this feature should be added, they never replied anymore as for today.
Frankly I would look for a more serious company with a more proactive attitude.
For handling tasks, bugs, feature requests, etc, you could use YouTrack from JetBrains, for instance: maybe is not free (something that is not always a bonus!), but really well made and with a very good support and it gives a similar experience as Asana, but way better.
Did you even try any commercial tool?
WPMUDEV already have quite some issue with support and developing.
Maybe you could start thinking to use a more "accredited" company and start using some tool that gives your users a way to see what you're a doing.
I won't get tired to say it: start being more transparent to us!
Even if you will start using a public bugtracker, as long as you keep a separate private system, I will feel you have something to hide.
Really, this make me feel you don't trust us and this is lowering more and more my trust in you (and is really little already, after a year of disappointments).
Stop promising you'll do something and please, start doing something.