We have various bug trackers floating around, but none are public unfortunately.
I guess there is nothing to hide there, so would be great to make them public; even huge projects like Minecraft has a public one (btw, this is my favourite, i also use it)
projects like MC have people who are actively sorting, comment, merge, etc, these opened bugs and do a lot of work to maintain these bugtrackers.
I guess the dev team here has not much time dealing with this extra amount of energy putting into managing a public bug tracker. Even something like an issue tracker like in git hub can be time consuming as hell if you "need" to make it working efficiently.
But i see the point in having a public tracker, too.
As far as i know they use the forum or direct input they get from their users and create bug-entries in their private trackers by themselve, so that they dont need to deal with proofreading, checking of legit entries, etc. If its in their tracker its a thing they know about, will hopefully fix, change or work on in the next time ...