Because they seem like a horrible scam seeing how they don't actually come with ice cream:
So yeah the deal is you sped about $3 for six chocolate flavored taco shells, with sprinkles, and chocolate sauce included, but you have to add in your own ice cream. It's the same deal for the "dessert nachos," in that they come with the chips and cinnamon flavored sauce, but no ice cream. Also I just want to go on record and say that I think those chocolate shells looks hideous, and unfortunately I couldn't find any pictures of the dessert nachos.
Oh and I should say that these aren't being sold in Taco Bell. Instead they are being sold at discount retail stores like Walmart and Target. Seeing how I don't really spend that much time in those sorts of stores I'm wondering if anyone has seen or tried these. Is this the next Oreo Dessert Pizza?