You're right that bus travelers would like a seat. You're wrong if you think that the majority care if there's a stroller or walker on board. So long as they get a seat, and even when they don't, if their fellow riders are being respectful - IE not clipping their toenails, causing fights, yelling loudly, etc, I don't think who is making use of the accessible seating area is of much concern to the general ridership.
I'm glad you've taken the false claim that you are a transit operator out of your signature. For the public to think that actual transit drivers believe for a minute that young families and those with mobility impairments don't belong on the bus would negatively impact the perception of transit drivers in the eyes of many.
To suggest that the system's capacity issues are due to making the vehicles accessible and equitable to all, and not an issue of insufficient funding to keep with ridership and population growth is morally wrong and plain ignorant.
Welcome to VV!