Let's use this analogy *ahem* Forums such as ea, iw, Public Forums, are like a college frat party. Everyone can get in and it's utter chaos. There are very little rules so everyone just makes a mess of things like pissing on your furniture. The members/(mods) don't do anything about it cause they are passed out on the toilet or in the hallway from drinking too much. Thus, more pissing on lamps.
Now for us...we are more like a private club. We have rules to make sure things run smoothly. Sure some of the rules "suck" but it's for the best of the forum. We don't accept people here that just use us for booze (aka Youtube Sub-whoring). This "small" community keeps people coming back to us and if you notice there are a lot of close not so in real life friends.
If people have something to contribute and make our community better then a trial period should be no problem for them. With good contribution the site patrons will be more inclined to watch their videos. So basically it works out the best for everyone this way.
(Just for clarification I have nothing against fraternities as I was in one. However mine was a smaller fraternity because we used discretion when accepting new members. Kinda like this forum
)