TheIzzardKingBecause it scales very well with headphone amps while still being low enough to be used with portable devices.
UPDATE: Oops! Just realized you might have been talking about the 250 ohm version. The 250 ohm version is supposed to be more detailed. I have never listened to that particular one though.
TheIzzardKingThe 250-ohm version, when driven with a desktop headamp, has a snappier and overall higher definition sound.
The 80-ohm version sounds like it "fudges sounds over" by comparison, even worse is the 16-ohm "DT 770 i", although they are all worthwhile headphones. An Objective2 is decent enough for the 250-ohm, I imagine that the Gustard H10 that drops from time to time is a little better for the 250-ohm.