There are definitely people who are capable of solving problems but whose performance drops appreciably under pressure. Now, you may not want to hire those people, but that doesn't mean it has anything to do with external motivation or making excuses, and you can keep your contempt for yourself.
There are many different kinds of pressure. The pressure in an interview is very different from the kind of pressure experienced when the database is down.
For example, I have no problem at all with on-site interviews but I choke pretty easily during phone interviews. I also have no problem with public speaking, but I have trouble engaging people I don't know in one-on-one conversations.
Appeal denied.
We don't ask trivia questions (what's the order of arguments to fputs, list all the overloads of foo in class bar) because knowing that (or anything else that's a 5 second lookup or context-sensitive help away) doesn't predict how someone will actually perform on the job.
Can any of us code as effectively on a whiteboard as we could in our favorite editor? I'd expect not, and if you were equally able on a whiteboard as in an editor, I'd wager that it's because you're not particularly good at either.
I mean, still coding without a computer - but it's something about standing up at a whiteboard. Maybe it's normally not so bad for me, but with the pressure of an interview, it's bad enough to give me problems.
I think my style is more trial and error, I make something and see if it works, if not I continue. So of course, a lot of great programmers actually are able to do that, but I think there are also a lot of people who work like I do.