It feels like when I'm trying to get a loan for a car and they won't give it to me because I haven't had a "steady job" for long enough, despite the fact I could buy it in cash with money for my side gigs, or put the whole thing on credit cards if I wanted to. It's two institutions whose values just don't jive.
Regardless, there's a lot of work in analyzing "risk" that has nothing to do with assets. Pull up a list of the most successful tech companies in the world 30 years ago. How many of them look like "AAA" bets today? Do HP or IBM look like solid borrowers in hindsight? At least (I don't think) they never defaulted on a bond. How about DEC or SGI? Even Apple Computer itself went through some pretty lean years where it looked like a pretty bad loan risk during that period.
The point is that companies aren't like economies that can sustain themselves on scale alone. You just can't tell what market conditions (or just plain mismanagement) lie in Apple's future.
In practice this doesn't happen because large single-item purchases should be denied, especially if they're unusual. If you generally spend $500 of your $10,000 limit on an average of 20 different items, and suddenly try to put one $5,000 item on your credit card without calling your bank ahead of time, it probably won't go through. Source: I worked at a credit card risk department at a major bank.
PNC Bank wouldn't give me a $10,000 loan to refinance my 6% car loan down to 2%. American Express continues to keep my Platinum Card open with over $75K in available credit. I make well into the $200K/year range.
Risk analysis? Hah.
EDIT: I have the $10K sitting in a PNC savings vehicle, and was still denied.
Also, there's some serious caveats and differences here. If it IS a charge card, you'll have to pay it off within 60 days. If you don't, you'll definitely see some adverse action from Amex not to mention a HIGH apr. Even if it is a revolving card like the Amex Skymiles Plat or the MB Plat, if you start revolving a 5-figure balance Amex will most likely investigate and you could get investigated (a request for your 1040's) and/or see some adverse action.
Finally, Amex has a lot more sophisticated risk models than other lenders, because they have to. I can charge as much on my Amex PR Gold card as all of my other credit limits combined -- just about $100k. They aren't as Fico reliant.
Have you seen your Fico scores recently? (There are about a dozen different true Fico scores, and endless knockoffs that are useless). If you've seen your Fico from something like MyFico.com and it's over 700 you could still have a problem with the Auto Enhanced Fico product that many lenders use for auto loans. That scoring model emphasizes installment loan history which it seems is your sore spot.
If I were you I'd head over to CreditBoards.com and learn how to clean up the negative info on your reports and get your auto loan problem fixed up.
http://www.bloomberg.com/news/2011-09-29/google-joins-apple-...
Until the US misses a debt payment, it should still have maintained its credit rating.
Part of the problem is that banks often have to build their models off of data that isn't sufficiently granular. For example, most banks don't have the ability to distinguish between someone who misses a utility payment because they're absent-minded vs. someone who misses a payment because they're short on cash. Regulations compound the difficulty to some extent, but it's really primarily a data/technology problem at this point.