The reason a pay-to-win game model is bad is because it is not a good long-term business model. Many of the pay-to-win games from KR struggle to survive on western markets because fewer people are willing to waste money to progress with pixel items. Then when they find themselves unable to compete with people that drop their paychecks on the game, they lose interest and leave.
The population in this game has gone steadily down as it has become increasingly pay-to-win over the years. I hear a lot of people acknowledge they enjoy the base game, but hate the company that runs it because it has gotten to the point where you either drop massive amounts of money on the game to stay relevant or grind until you are numb. Even with UE4 at our doorstep I know many people that have little interest in continuing to grind.
Having a few people willing to drop massive amounts of money every month may keep the servers up for now, but this game could be thriving if it catered to a broader audience that was willing to spend a reasonable amount on the game for cosmetics or a worthwhile premium subscription. Both of these facets are ignored, one with an almost non-existent rotation of content and the other being incredibly outdated and nearly worthless.
The people that are willing to spend massive amounts of money are not necessarily the ones that ruin the game for others so much as the pressure the company puts on the player base to spend money. They make progression increasingly time consuming while dangling the easier method on a golden stick. Just swipe and you can save hours of mind-numbing grind. It's what has been slowly turning myself and the people I enjoy the game with away from the game.
There are a lot of reasons games like FFXIV have, on a single server, more players than EU and NA combined, and they have ~20 servers for NA alone. The fact they are NOT p2w is probably high on the list.