plan confirmation

I'd just like to expound a bit on the concept of plans. When one makes plans, whether they be personal activities or professional meetings, it is incumbent upon those involved to be aware of these plans. That's the reason plans are made in the first place, no? This whole concept of confirmation is ok when both parties connect, but some people take it a little too far, particularly when they call to confirm within say a few hours of said appointment. I am particularly frustrated with one such occurrence which has me twiddling my thumbs for 20 minutes til a friend/date/who-knows-who arrives. I had left my phone in the car and he called 15 minutes before we were supposed to meet, saying "call me back." I thought there was some reason he was calling, like he couldn't make it, or he would be late or something, and being the one who left my phone in the car, was fully prepared for that. It turns out he was just waiting to hear that I was here, that I was still wanting to get together (for dinner mind you, and you know what I get like when I am hungry). Why did we make plans in the first place if you are just going to base it on whether it is confirmed immediately before?? What if one is out doing other things, structured around the plan of being somewhere to meet someone at a certain time?? It is my responsibility to let you know if I am going to be late or whatever, a responsibility that I fully accept, and hold dear as part of my anal retentive side for that matter. Let's not overlook the reality that I rushed through the end of my day, saving things til tomorrow that I could have done today, to be home in time for 5:30.
This has happened to people I know with job interviews and work meetings too, as if those people didn't have anything better to do than sit around waiting for the plans to be confirmed.
It just gets under my skin, and like I said before, doing that at a time when I am hungry? Not a good move.