I disagree, I don't really want the signing key to be $0.99 and someone just making 100+ developer accounts that can't be tracked with some leaked list of SSNs or similar. That would negate the whole point of the signing key for the end user almost entirely.
Is proper identify verification something that Apple can do at a marginal cost significantly lower than $100?
I agree that the $100 fee in no way guarantees proper identity verification has been done. I also see plenty of other unnecessary barriers the fee creates, I just don't know what an obvious alternative would be.