Since both AWS and azure some free tiers for a trial period, what other way do you see for them to ensure you aren't abusing the service and just creating a new account every month? Tying it to real financial accounts is unfortunately the easiest way to make that work.
Yeah, and MS is always after that sweet business 'moola, so they really want your boss's credit card. You get so many features out of the box with azure, and the free monthly credit to use them, it's no wonder they have to tie it down somehow even if it makes it an obstacle to a lone dev who just wants to try it out.
