No mannerheim is correct , you are saying yeah but some people can't.. but his solution solve the issue , if you want to register under tor over anonymous and secure mail system having 5$ Monero is the easiest thing to procure.. there are communities that trade for cash or you can even mine anonymous there may be other alternatives.. but one solution to avoid bots doesn't exclude others you as subscriber should be able to choose the one that fits to you so saying some may find it difficult doesn't say that this solution is invalid . Just that maybe must not be the only option available