Ultimate shoulder rides

On my way to this Community via Google, I noticed a website above this one called 'Sitting on Shoulders (Facebook). I took a look and I was surprised by how many females were sat astride other females' shoulders. Some females are by nature natural subs (submissives) but I was still surprised by how many seem to like to have another female sat astride their shoulders. Is this normal? Surely, guys should be carrying females, particularly at music festivals, but this does not seem to be the case.