Tibco versus TCP (Rendezvous/RV)

I cannot understand what is so special about Tibco.

Their marketing material stresses that TCP is a pessimistic transport protocol which does not require client acknowledgement of receipt. How can this be true?

To me Tibco is basically a TCP protocol backed by a queue.

Can someone please help me understand the main selling points of Tibco? I am about to have a rant to my manager telling him we are being completely ripped off here.