Some people thrive in an open office, while others can't function due to distraction, interruption, and an expectation of constant interaction. Some people thrive with private offices and doors, while others go stir-crazy and feel like they can't collaborate. And cubicles with proper separation end up as a satisficing solution that doesn't make anyone completely happy but doesn't drive people completely crazy.
Ideally some kind of hybrid could work, with doors available for people who want them, and common work areas available for people who want them. But perceptions matter too, and "private office" rightfully looks like a perk; many who might function better in a common area might resent not getting an office.