I have recently been on an Air China trip with my family, I think on an A330 aircraft. We had a baby bassinet and thus were seated in the front row of a cabin, and got seats in the middle of the aircraft - like row 48 D/E/F/G in this seat map.
As usual, the bassinet was mounted to the wall in front of us, as were the poaches with magazines. Our tables and displays would fold out of our armrests.
To our annoyment, during the flight, we noticed a constant flow of fellow passengers who seemed to consider the space in front of our seats as a public passageway to travel between the starboard and port aisle - even when the bassinet was mounted and our tables and/or monitors were extended. (The unfolded table/monitor would extend forward far enough to be slightly underneath the bassinet. Visually, this arrangement unambiguously communicates to us "no way through here" and we perceived trying to squeeze through there as quite a bit rude, but plenty of other passengers seemed to think differently.)
At some point, we were fed up with the situation and started kindly telling people that this is not a public passage and they need to cross over somewhere else, which they all gladly complied with.
Cabin crew (some of whom were seated right next to us on the crew seats) did not intervene or comment in either situation, making me think they were okay either way as long as passengers could come to an agreement among themselves.
My question is about whether there is an "officially intended" guideline. Is the described space supposed to serve as a public passage when someone is seated there, or is it supposed to be more or less exclusive to the people actually seated on those four seats, or is it intentionally left open and subject to negotiation between passengers?