The more it goes the more players switches games faster.
Not that they don't want to play their "old" MMO anymore. They want to see new virtual worlds, experience new content, or wait till games get "fixed".
Some of us subscribe to the publisher's newsletter. Though there is barely one letter a month and lately patches tend to be delivered faster than ever.
Another issue is, the complete list of the patch notes are sometimes only accessible to subscribed players. You have to do your homework and search for them on players topics.
I remember a few times when I accidentally found patch notes of a game I didn't play anymore... to finally pull my credit card and log back in.
Don't you think It would be interesting if you could subscribe to get the full patch notes delivered to your mail box?