Ziggs's minefield lasts too long

Ziggs's Minefield lasts 10 seconds and there is a 16 second base cooldown for the ability. With 40% CDR, isn't that a 9.6 CD? Or in other words, endless fields? For comparison, Jinx's Chompers last 5 seconds, half the duration of Minefield and with about a fifth less coverage of the map (not to mention the 0.7 "arm" nerf, despite the fact its eventually "hard" cc). Can we please get some kind of balance tweak on Ziggs?

My thought is a scaling rank 5/6/7/8/9 second duration, or a flat 7 second duration; really anything less than 10 seconds. The change would force Ziggs to be a little more tactful...if having a 4 second base Q at Rank 5 with 1400 range wasn't enough to think about Q.Q. But seriously, Ziggs has it too easy while zoning. His 10 second Field is too much.