I think people left for a lot of reasons: better free/cheap games, the removal of the successful PvP system (by the time it came back the community was largely gone), and a long period of time without many interesting updates. It felt like for multiple years Jagex was just trying to provide adequate replacements for the old Wilderness (volcano bounty hunter, clan wars, pvp servers, bounty hunter pvp servers, removal of pvp servers blah blah), and as a result worked really hard on content that really didn't satisfy the old pvp customers. As a result, people not interested in PvP, but rather quests and monster hunting (myself) went a long time without much new content (corp beast and nex were 2.5 years apart) and eventually moved on.
Jagex's new business model seems to be: small customer base, get lots of money per customer, instead of the old have a massive number of members all paying a little bit. Even though they're still making a lot of money, ultimately I don't see that ending well because you can't count on someone to shell out tons of money forever - they will need to recruit new players, and so far as I can see they aren't, really. The F2P is massively outclassed by other F2P games and they really need to spend time on it to make it competitive. Until then the attrition will continue.
- Fallstar likes this