Well, Pozzovivo and Igor Antón are pure climbers too, but I guess we're talking about pure climbers who were genuine threats to win any GT they entered and who the big guys feared. Herrera was probably the last of that mould; Pantani and Simoni may have been riders you could class as pure climbers though.
El Tarangu was not the last pure climber, but for me he was the best. One of the all-time greats, a man who could put the fear of god into even Eddy Merckx in the mountains. Bickering over the title of 'last pure climber' is irrelevant; somebody could always emerge to reduce the title to meaningless by being a pure climber themselves. Maybe Quintana will be that man. But José Manuel Fuente is, and will remain, one of the finest examples of a rider who exemplifies what is great about our sport. The pain and suffering of one man against the mountains. The attacking, and the epic rides, reducing the field to rubble in his wake.