That would be about as effective as news websites that require an account to read their articles. Depending on how they block access, I simply hack around it, or just go somewhere else

There's really no reason to block non-members from viewing content, unless the cost of bandwidth is prohibitive. Viewers generate ad revenue, regardless of whether they are logged-in. Non-member viewers that like what they see spread the word to others that may become contributing members, or at least more ad-revenue-generating viewers.