As a current player, I feel a lot of the bad things talked about Jagex are more on the management side rather than the development side. Most of the known OSRS devs and community staff are held in pretty high regard, and my limited interaction with the RS3 community suggest some of the same. The most regular complaints are about how many microtransactions are in RS3, how poorly the devs are paid (though, that's also the video game industry as a whole), and specific events that seem to be very much streamlined through by management and then later patched up after community backlash.

Some changes do get into the game without player approval. The idea behind them is that some changes are necessary for the long-term integrity of the game (in-game economy, gear balancing, etc). They are always controversial.