Have you actually talked to educators about this?

I've asked a few why OO is the first thing you learn - and the reasoning was two fold:

1) People that start off by learn imperative programming end up writing really really shitty OO code. They're they type of people that end up copy and pasting stuff everywhere. It's really hard to get students to not take the "short cut" of copy paste to think in objects when you have homework deadlines and other things to worry about (and the teacher never actually spend time to teach you how to use programming toolchains...)

2) it's conceptually one of the biggest stumbling blocks for people. A lot of people have trouble wrapping their heads around OO. So sure you could teach it later, but it'll never sick or sink in.