For me it's not the weight, considering there's actually very little material in what is basically a tiny tray with a small pot stand attached. In either material it'll be lightweight. For me it's the strength of even thinner titanium. I've got various stainless steel and a few titanium stoves. I've yet to break a Titanium stove.
Don't get me started on the benefits of Titanium pegs over steel or aluminium alloy ones. All my alloy and steel ones end up looking like a corkscrew with all the times I've had to straighten them. Rarely needed to straighten Titanium pegs, not least because I can carry decent ones for lower weight.