Yes, the cable connection is stupid located, because I can not turn the head around without disconnecting it. Why do not rotate it downwards instead?
Sometimes I want to rotate it to get the ir-sensor the other way.

It's pretty much the same configuration as the power connector on the Esprit 2 monoblocs I have.

Yes, as you point out, it does stop you from flipping the head over in elevation, but I can't say I have ever wanted to do that myself. I would normally pan it around 180degrees in azimuth instead, so as all the controls remain the same way  way up. If you have a large light modifier on the front, then it would be difficult to flip over, especially in locations with limited height.

However the way it is configured does have the advantage that it allows you to neatly route the power cable down the bracket and the ligting stand keeping it out of the way of the controls.