I struggle to believe that they like the game. I have repeatedly seen them essentially say they want FFXIV to be FXI-2. XIV and XI are completely different games. It's like complaining about how FFXV isn't FFX.
It's one thing to see people criticise the same handful of things over and over again, and it's another thing when a person repeatedly criticises so many aspects of the game that if the changes they wanted were introduced the game would become unrecognisable.
Uhhh...1.0 flopped hugely because it was borderline unplayable for a long time. There were massive server issues and the game itself crashed a lot due to demanding far too much from hardware and for being badly optimised in general. No matter how great a game itself is, if players cannot play it then they're not going to like it.
Furthermore there were quite a lot of issues with the design itself because SE literally ignored player feedback during testing. The ui had too many dialogue boxes to go through to do simple tasks, the combat was clunky, gathering was almost purely rng (because for some reason the devs thought it would be great if players didn't know what they were gathering???) the story wasn't fleshed out at all (which is a crime for a FF game!), navigation was awful due to zone and map design...I could go on for a long time. It's a very long list that is very well documented.
SE wanted to create a successor to XI with 1.0 XIV but it failed miserably because the game was poorly made and was nowhere close to being a finished product. It was a controversial game right from launch, and the reception was so bad that SE was in danger of falling apart as a whole. I know people who adored XI who tried 1.0 XIV and they all agreed it was awful, even if you were lucky enough for the servers to stay online or for the game not to crash. The improvements to 1.0 came after SE removed the original 1.0 staff and replaced them with a different team lead by Yoshida. However the devs and Yoshida saw that the game was so badly made even down to its foundations that the only way to save it was to scrap it, which is why 2.0 was released as a different game, not as an expansion.
Sure a lack of advertising did hurt 1.0 XIV but what hurt it the most was the sheer arrogance of the original team who knowingly released a horribly made unfinished product built upon ignoring player feedback, and they were expecting to ride the prestigious Final Fantasy brand to success. Unsurprisingly this mindset hugely backfired.
Anyway...would you even want to heavily advertise a disaster of a game that put your company at risk of dissolving? No, better to stick to focusing on the die-hard fans who stayed and were willing to provide feedback to lead the game to a better place. That's what SE did, and it was a success.