Could the fact that Apple pretty much force you to enter your credit card number in their system play a role ?

You used to be able to create an account without it, but not it seems impossible (or if it is, you have to do some devious thing 99% of the population could not figure out, even after solid googling).

> or if it is, you have to do some devious thing 99% of the population could not figure out, even after solid googling

That "devious thing" is "attempt to download a free app without an account". Then it will present you with the credit card-free option.

You can definitely create an iTunes account without a credit card. I just did 3 days ago.

That has changed recently. With the recent Angry Birds Space, they have a 'premium' option for 0.99 and it has a healthy 500,000-1,000,000 downloads.