observe:

http://www.alexmoulton.co.uk/

now then, as we see the chainstay on these bikes slopes UP to the bb - reverse drop. it does so because of the small wheel.

perhaps you are cofusing "bb DROP", with "bb HEIGHT". they are not the same thing. "bb height" would fit your assertions, but not bb drop.

bb drop and its relation to wheel size is observable on that moultan, and on the bikes at the top of this thread, just as i said.