Because it has just shipped the 20,000th unit of its midrange Scalar i500 tape library. Even with disk-based solutions, including Quantum's own DXi line, taking most of the mindshare for backup destinations, the fact that Quantum could sell 20,000 Scalar i500s in two and a half years is proof there's still some life in old-fashioned tape.Quantum got the i500, along with the rest of the Scalar line, with the acquisition two years ago of ADIC. Curiously, the modular design of the i500 was developed in part to allow ADIC to better compete with Quantum's M series of modular libraries.
I'm a big fan of modular libraries as they give IT departments the ability to add slots, for capacity, and or tape drives, for performance, in much smaller increments and over a much wider capacity range than traditional libraries. In my consulting practice I'm frequently called in to help organizations fix backup processes that are completely broken, making it difficult if not impossible to guesstimate how big a tape library they need. As a result, I end up recommending a modular library so we can add capacity as we learn we need it and the organization's needs grow.
With the i500 I can start a client off with the 14u cabinet that holds up to 128 tape slots and 6 LTO (even Quantum's giving up on DLT) drives and add 5 and 9u expansion units to add additional slots and or drives while still managing one library up to a full 42u rack with over 400 tape slots.