Danny.
You seem to have been equally lucky and unlucky in your travels.
To have never spent 30 minutes queueing at any airport in the world means you have been extremely lucky.
And the equally unlucky that the only queues you have had are at MAN T3. Of course, I do detect a slight element of porkies as I do genuinely fail to believe you have NEVER queued 30 minutes or more at any other airport, I just don't buy it at all.
Now, I know T3 is not perfect, not by a long shot, and I'm certainly not trying to portray it as such.
What I do have an issue with is this 'inconvenient', or 'worst in the world' tag and so on.
Yes, I have waited over an hour at MAN before, but that was one single occasion, on an early Monday morning last year. On average, my wait seems to be about 15-20 mins, but on a fair few occasions, have also passed through in about 6 minutes.
Now, as said, MAN is a long way from being the worst. I've travelled in the region of 150+ airports, and the worst were Accra, Lagos, Jo'burg, Los Angeles (pre revamped TBIT), Las Vegas (pre new terminal), Delhi, Mumbai and surprisingly, Sydney.
I've seen media reports that BHX recently had queues of over one hour, and I've been through LHR T3 on 2 occasions where I had to wait over an hour also. Hamburg was also a surprising one where at least 3 occasions it's been over 30 mins, because it normally runs quite smoothly and never seems overly busy.
So yes, T3 is far from perfect. Frankly I'd rather it be the first terminal to be knocked down and rebuilt, and plans I've seen suggest it will be rebuilt after the T2 revamp, but, it's also far from being the worst airport both aesthetically and security queue wise. Those saying it is the worst airport must have either just transited the good airports or had their eyes closed.