We have a setting for this we call "Aviator View." Currently, as you point out, airline flights attempt to show gate-gate times by default, since those are most relevant to most travelers, while GA flights show air time since gates don't really apply. By enabling Aviator View, all flights will be shown using the GA format.
To enable this, click the gear icon at the upper center of the flight page to open your settings:
Then check "Always show aviator view:"
This will switch to a more condensed layout which also always shows gate times for the flight progress bar: