Because its proven to OSRS GP work. Without updates like this the game would be dead, not only from a game perspective however from a commercial point perspective. Jagex is at the end of it all, a business that must pay workers and earn a profits. It would be quickly outpaced by its rivals if it didn't maintain the runescape.
All things are dependent on progress and adaptation Technology makes this even more essential. It is easy to say that humans are the most dominant race due to the changes they have made to their surroundings. But that is quite a different story.
I don't have any idea how old you're, but think about the past 20 years. We, the technology users, have had the need to change. This was accomplished via VCRs, CDs and DVDs as well as different interfacing devices (touchscreen, for example). In the age of technology, which gaming falls into the category of, adapting is essential for the player. It is your desire for Runescape to keep up with its competitors and survive for a long time. But with a backwards attitude that "no major changes because they do not have the same technology as our game", runescape will slowly fade away.
EoC isn't the main issue. It's simply more clicking to get the same result. The highlight of the game is the ability to queue emotes. WoW I use 80 odd keys and there's a mini-game in working out DPS improvements or working out new strategies in PvP. Although I'm not a fan of the idea of controlling enemies' minds from cliffs, it is something I like.
It is important to understand how EoC came about. Its birth is exactly like Solomon's and SoF. This is what was forced upon players. Recently, one Jmod posted on forums about a poster that revealed bugs in BA. He said that it was constructive feedback. Later posters remarked that all the bugs were discovered and sent to Jagex in the beta, yet they still made it into the live version.
So players weren't involved buy runescape 3 gold in the beginning, some two years ago and neither at the end. Runescape can't be successful if it doesn't consider players. EVE Online doesn't, WoW doesn't. Both games provided me jaw-dropping experiences when compared to Runescape. So I don't worry about the survival of EVE or WoW. "Because it's been proved to be effective. Runescape wouldn't have been created if this argument was applicable to new updates. MMOs have been around for over 15 years. This is a short time to have traditional panaceas.