You're talking about market percentage, I'm talking about actual realistic uses. Even in home environments, it's nice to have a closed back with greater isolation just in case someone else in the house is watching tv, you have the dishwasher running, you have kids running around, you have a dog, etc. Outside of the home environment, you can take your high end closed back and use it as a transportable if you work 8hour days in front of a computer in an office.
Open back's been the default for the purest audio quality because it's easier to control resonance that way, but I'm happy to see people like Mrspeakers and Audeze putting more R&D into the idea of closed high-end audio.