Lack of Advertisement would be the biggest reason
but the thing with this graph is that it's for "Unique Visitors" to the Runes of Magic Homepage. Not the population of how many people "log in" or it could be that stats site doesn't take into effect on how many people visit the forums directly (without going through the homepage; Via Bookmark, google)
Check out the Results for:
Gameforge
So this really doesn't mean "RoM is Dying", i really dislike Doomsayers shouting such things and used to be a well enforced forums rule that doomsayer threads would be autolocked (before Gameforge). But yeah, i think Gameforge should do something soon to help boost traffic to the site/interest in people
Other things to think about tho
- Playstation 4
- Xbox One (coming out in a day)
- Battlefield 4 (PC)
- Pokemon x/y? lol idk
- Other Popular Game Title Releases and Updates
There's just been other things taking up peoples gaming time that factor in the drop in Players. But one things for sure, some players ALWAYS come back no matter how many times they "Retire"