IRISHEMIRATE
Thanks for your rundown of the day. I agree with everyone who has said don't give up. I think if one thing is clear, there is often no way of knowing why someone was or wasn't selected to progress within the recruitment phase. However, i don't think this is exclusive to Emirates. If you look at pretty much any of the airlines' recruitment threads on this site, there is usually at least one person who says they applied and didn't hear back/made it through all the assessments and 6 months later were told "no thanks"/turned up totally unprepared and wearing a leopard print jumpsuit and made it through/etc.
I think the reality is that most recruitment events, but particularly Open Days, are simply a means of efficiently (but not always effectively) processing a large number of people. I don't think that even Emirates would claim that they identify all of the good candidates at every Open Day. Some good will miss out, some bad will progress. I don't really envy the recruiters: they must have a very difficult job trying to identify the good from the bad simply from photographs and a resume.
But don't give up. I wouldn't think that your experience with EK recruitment is necessarily representative of the entire company. With one of my current employers (non-airline), i applied for a job, went for an interview and after not hearing anything, I eventually called them 4 weeks later to find out the outcome. I've been working for them for 4.5 years without any major problems. But if i'd let their recruitment processes put me off...
So, in a very roundabout way, i really am trying to say 'consider reapplying'.
Samara
The age limits question seems to be a tricky one. I'm sure that someone who works for EK (OzyOS, EKHQ and helfsich all appear to be very helpful) will be able to tell you more accurately than i can. However, if you haven't already, you have nothing to lose by simply applying and/or turning up for an Open Day, if your circumstances allow (eg money, work, family). If you aren't successful, it isn't necessarily because of your age. But if you never actually put yourself forward to Emirates' by applying, then you'll never know. Go for it (again, if you haven't already)!