The policy exists for a couple of reasons.
First of all, not allowing generic addresses like "info" and "support" is generally considered best practice, largely because these addresses are so common that they are very likely to be abused and most UN-likely to be properly opted in. So to help keep deliverability up we mandate best practice.
Secondly, such addresses may well be group addresses. So say person "A" on the "info" group opts in. FeedBlitz then mails "info" and A, B and C all get the updates. Well, B and C didn't subscribe, and so they view the email as spam and report it as such. Or one of them unsubscribes, which then stops them all from getting the emails because as far as FeedBlitz is concerned "info" just unsubscribed. FeedBlitz doesn't know that "C" unsubscribed but "A" approved it if they share the same group email address.
So using generic / group addresses is a bad idea simply because the other recipients in the group are much more likely to view such emails as spam and then complain or unsubscribe.
Therefore, in order to ensure that the mailings from us reach the right people who want them we don't allow generic addresses (and, for the same reasons, we don't allow subscriptions to lists like Google or Yahoo group addresses, or addresses that look like old-fashioned listservs).
We are happy to accept subscriptions from potential subscribers using non-generic addresses.
The net result of this policy is that your emails reach the right people and deliverability remains high because complaints are kept low.