Because there's absolutely NO reason to. There isn't even an upgraded set of turbos that one can buy that could even begin to utilize the extra flow the cams would provide. The stock turbos can be easily max'ed on the stock cams.
07 997 TT 6MT, Arctic Silver/Sea Blue: AWE exhaust, GIAC flash, H&R, 19" BBS CH-R in widebody fitment
09 E92 335 M tech 6MT, Titanium Gunmetal Alufelgen SF 71s, Helix FMIC, JB4
Deposit placed on '15 F80 M3