Well I won't even comment on the entire tenor of your message - this goes down the entire kids in first class, kids in fancy restaurants, whether my kids are better behaved than many adults, etc., which has been kicked to death many times on this forum. I will point out that the Four Seasons San Francisco specifically suggests that they cater to kids, which makes this room occupancy policy simple nonsense. For example, all of the following comes from their website:

Whether yours is just beginning, all grown-up or at any stage in-between, Four Seasons Hotel San Francisco is a wonderful base for your family. We go out of our way to make our youngest guests feel welcome, and our resourceful Concierge is always close at hand – to make reservations for a family dinner, offer suggestions for tomorrow's outing or help arrange a babysitter. Children under 18 can share their parents' room at no extra charge.

Children's Amenities

Before your stay, simply provide us with the names and ages of the children in your party so that we can be prepared with:

Welcome milk and cookies for our youngest guests
Child-size bathrobes
Complimentary baby and children's toiletries
Children's menus in our restaurants and In-Room Dining

Upon request, and subject to availability:

Items to childproof guest rooms
Cribs and/or rollaway bed(s), at no extra charge and subject to maximum occupancy
In-room PlayStation and games through "On Command" TV for a fee
Children staying in separate rooms from their parents will find the standard refrigerated private bar replaced with a snack bar designed especially for kids