To perfectly comment about this issue, the evil fee paid should be the first line of discussion. I am not sure this forum is not growing bigger, but it is not grow as much as it should, simply because of the evil fee. The stale members that want to open another account knows how to bypass the evil fee, but the new members that just want to register do not know how to bypass the evil fee. Many people do not make use of this forum just because ransom is demanded for to pay evil fee. About this community growing, I do it not think it has anything to do with forum software if evil fee is still being paid.
Its a preventive measure that most certainly does what it was implemented to do. Reduce the amount of users registering from a IP which has previously been associated with breaking the guidelines. However, I do agree to some extent that its probably not the perfect solution. I would much rather a shadow ban system, which may increase the workload of the staff, but would not effect the majority of the users on the forum, plus with a shadow ban system, you are effectively checking each user, and prevent many more users that might have malicious intent. I'm sure there are, and has been times when a user that wanted to join the forum with malicious intent as their primary goal, were willing to pay the fee if they profited from it. I'd like to see a shadow ban system which is only lifted manually, and not just after one good post, but after multiple posts or from moderator discretion. You could argue that it would be a much more restrictive approach to newbie jail, but I think with some thought put behind it, we could probably achieve what the evil fee is doing, and more.