By your logic people shouldn't be using Linux, Windows or any other software because people have found exploitable bugs in them. There has never been a backdoo

By your logic people shouldn't be using Linux, Windows or any other software because people have found exploitable bugs in them. There has never been a backdoor in Pidgin. Instead Pidgin has a very healthy security community and they release several CVE's each year. I would use Pidgin over Tox without a blink since Pidgin has been around the block longer (almost 10 years now) while Tox hasn't released a single Security advisory yet. So I'm sure there's a lot of "low hanging fruit" exploits waiting to be found in Tox.