I missed my dd2's first nativity, I was working, it's just the way it is, and plenty of people can't go in for every event, and not every parent is there, even for the nativity (plenty of dads missing and not feeling angsty about it).
I usually try to either go myself, get my husband to go, or another relative (granny) to these events, but I also don't take on the entire responsibility for attending myself, it's a whole family thing and women are sometimes too quick to blame themselves and apply guilt if they simply can't attend for work reasons whereas dads are considered absolutely amazing if they do attend, double standards at work for sure.
I also agree with you that asking for time off, when you have children, can be difficult if your position is insecure, you need to keep those times off for real emergencies (such as your poor friend, or sickness bugs, or other emergencies). In an ideal world, you would be able to work flexibly and your boss would be understanding, but in the real world, you need your job and you have to do what you think best to keep the money coming in, especially in the middle of a recession.