Double-X Kodak's cine mono still has a tungsten and daylight ISO.
Probably for three reasons
Think it is quite blue sensitive
The cine people are more critical on exposure than stills
Not many people use tungsten studios?
I think your second reason is the most probable. The difference between the two values is only 1/3 of a stop. The fine grain positive stock on which the negatives are printed has little latitude. Still films probably have similar values but it is not critical for still exposure.
A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.