OSRS has existed a very long time so far as games and software goes RuneScape gold - and even though the client is bad and obsolete, it's an integral component of the experience of what OSRS for a lot of men and women. For many users, if they updated to a client it would lose the sense and individuality of what's OSRS. Do not piss off your present customers. OSRS has practically no control appeal for anybody who hasn't played RS and I would be missing if they took away that which made it feel like the OG. If there was a client update I'd be fucking lost and would not feel as inclined to learn that the janky system all over again.
Additionally, a third party customer buy-out could bring about an increase of third party development which is not exactly what Jagex wants, not just because people will cheat but for security of its customers as well as the company pride. Generally, purchasing a company because they made something better to the game than you did yourself isn't going to impress any investor regarding your internal development team and leadership team. Why didn't leadership have one made sooner and identify this if they need a customer?
Not taken Camertime but I will respond to your points also. Fully acknowledge I tried to validate my opinion using a title I have made. Saying something is essential since it pertains to the first game that was tried to mimic is a good point. Yet, this edition of runescape has changed cheap OSRS gold from that which 2007scape was that doesn't hold as much weight. Also, stating something is obsolete and awful pretty much supports you should probably consider something.