Here's an example. We flew from MPS to LAX (via DEN), round-trip, in January. It was a week trip. Driving (both ways) would have taken us the entire week, so flying was really our only option. On our return trip, there was weather in Denver. As a result, a lot of flights were delayed/cancelled, and the airport in general was a cluster####... Lots of pissed off people, trying to fly stand-by, etc.
While waiting for our flight (which was delayed), my wife got into a conversation with another couple, who had a 2YO and a 6MO. The wife was in tears. Their flight (the day before) had been cancelled. Their airline wasn't very helpful/accommodating in this situation, because the cancellation was weather-related, and not a mechanical issue. So, they had no choice but to rent a car, and go to a hotel (both on their dime). Their bags were checked, including car seats, and they had no access to them. So, basically, they had to drive the rental to the hotel, with kids, and no car seats. No bags, just their diaper bag and their stroller. Probably not a big deal to people without kids, but to some, it's a big deal. Certainly not the ideal way to spend a night in a hotel (not that spending a night in a hotel is ever ideal with two small children).
Then, when they came back to the DEN airport (after what I'm sure was a miserable night, given the situation), they were told that the best that the airline could do would be to re-route them to another airport... 2-3 hours from their original destination. So, again, they would be renting a car, it appeared (at least for that rental they would likely have their car seats back). The wife was clearly losing it, and her husband was stressed as well. They were on stand-by, but had about 7-8 people in front of them on the list.
Long story short (I know, not that short, but shorter than it could be), they made it on to our flight. Mom was (again) in tears, but this time it appeared to be more out of relief/exhaustion than anything else. They sat behind us on the plane. Their kids (and ours) were all relatively well-behaved, but at one point or another, at least 3 of the 4 were crying. The worst of the four was their 2YO, who essentially had a tantrum at one point. I heard the parents having what sounded like an argument... Not loudly, but just loud enough that I (sitting directly in front of the mom) could make out bits and pieces. It sounded, essentially, like she was blaming him for dropping something, and he was apologizing. Both were clearly stressed, and for good reason.
My point is this. For anybody not knowing what they had gone through, in the past 24 hours, it would be easy to look at that couple/family, and ask yourself WTF was wrong with them. Why can't they keep their kid under control, etc. But, in my opinion, they were holding it together quite well, all things considered. And, all things considered, they did a pretty good job of making sure their kids didn't inconvenience anybody else on the plane. At least, as much as they could, given the ages of their kids.
So, like I said, unless I can put myself in someone else's shoes (which is never going to be the case, at least not completely), I try not to judge. The same goes for the businessman who is clearly irritated by the crying kid. Who knows what has gone on in his past 24-48 hours (or what he has in store, once he gets to his destination). So, yeah, he has every right to look irritated. I try not to get too caught up on what others are doing, given that I don't know them (or know what they're going through). Flying is pretty much a miserable experience, kids or not.