You used be able to declare, with relative confidence, that what’s good for bot is good for the user. In this case, form driven navigation is difficult or unreliable for users with disabilities or low dexterity. Many forms also cause problems for users on mobile browsers.
That the G-Bot was also restricted from this type of navigation gave devs and designers the motivation required to avoid form-based nav. I fear that the minority of users affected by this type of nav, will not be high enough on the audience priority list without the Bot among their number.