What gets rewarded gets done. You know this because your game has incentivized you to do insane things that you would never have done on your own, like camp the same spawn for days or wake up at 4am to play an online game at just the right moment. (Also, job, you get money for being there.)
Your decision as a consumer is essentially binary: buy or do not. (There is no try.) If you are willing to give them your money right now, your message is that this product is worth what they are asking for it right now. MMO players are famous for complaining endlessly about games and then sending the $15 anyway. Because hey, maybe they will take the money as a sign that you have hope rather than that you approve of where it is right now, right? Mmhmm. Do you have a lot of products in your life that you buy in the hopes that they will use your money to get better later?
Maybe they will get the proper interpretation, that you are unsatisfied but consider it the best option available. All companies have competitors, and a new competitor or product might steal your business if they do not improve. Mmhmm. Or are you one of the two dominant MMO player types: sticks to a game for years through thick and thin, or jumps from new shiny to new shiny in search of The Game? There is some margin at which they need to fight to keep some customers, but that is just triage, and almost all the vocal players are in the “no help needed” and “no help possible” categories.
Your only threat is your ability to take your money and leave. Yes yes, and take your guild with you, we know how important and influential you are. The key thing is that you must carry out your threats. Talk is cheap, and years of indignant forum posts have devalued it further. Threatening to cancel is not threatening. It is a low-cost signal, something anyone can do with no effort, and without actually canceling. You will think of reasons to give it another month or two. That’s how human psychology works: you will rationalize why you should keep doing what you are doing. It works the other way too: once you cancel, you will find ever more things that they must do to regain your patronage.
This is not complex game theory. You have one tool.
if someone can find me that quote along the lines of “shut up and send me your $15 little man. I need to make payments on my Ferrari.” My Google-fu is failing me on an approximate quote search, and I cannot remember the site that archived fun bits like that. to commenter Afterhour, and having the exact quote led me to the wiki I wanted.