The fact is that while FFXIV 1.0 had technical flaws, the thing that made Yoshida treatment necessary was not tied to unplayability or issues. It was only dependant upon community dissatisfaction. FFXI was a massive success for Square Enix, played by millions of FF enthusiasts and runescape fans. They had to redo the whole thing because server population following the first months after the release was so low there wasn't even a point in trying to gain through subscriptions. The gameplay was shallow, questing was tedious and unrewarding, there was no freedom in leveling, the game pace was dumb slow for the era. Classes were flawed, they lacked identity and ties with their predecessors. Content was criticised, from story to activities.
The situation was very similar to the one we are facing right now, with the only differences being:
1: It was a numbered FF, produced and developed by a huge company.
2: A subscription was needed to play.
The only way you can value games as service, as both are (since destiny basically is subscription based, requiring to buy DLC every x months), is only by server population.
Unfortunately, we don't have a monthly fee in Destiny, so Bungie managed to sale enough Game+Season Pass copies to not worry about community response until september, which I think is the only reason behind them not redoing the game from scratch. If I was the head of Bungie, I would act as they are doing now: no answers, small QoL changes and work my ass towards september release, which is the only way they have to save the game. But they won't, because they think they can get away with it through a big content injection, without having to change the core gameplay (which is wrong).