So we have seen what can happen with a closed-source torrent client recently with this uTorrent mess.
I have been using Tixati for years now, and am a big fan of the program. I have tried other clients on occasion, but always return to Tixati.
It seems to be the most efficient client, I really like the interface and the features that it offers.

But why is it closed-source?

I understand that commercial software would be closed-source because they're selling a product, but in a world where privacy is becoming an increasing concern, I'm not sure that I wish to continue using a closed-source torrent client that is not under scrutiny by a third-party.

I am not accusing the developers of doing anything untoward with the program, but the lack of transparency does concern me.