Like i said, this is because you're a console gamer. A poll made in 2000 for example in a german magazine asked its readers which are the top 10 most well knowns game development houses. They were: Blizzard, Ensemble, LucasArts, EA, id Software, Bluebite, Westwood, Maxis, Bullfrog and Origin. How many do you know ? Id wager more than half you havent heard until now, besided blizzard, ea and id. Because PC gaming and console gaming were separate realms of existence then. So if you only played games on nintendo you would have the most gigantic blindspot regarding gaming that has ever existed.
I can also asure you with 100% certainty that those people that responded to that poll, nobody would have known what dragon quest is.
The ones I don't know about are Ensemble, Bluebite, Bullfrog and Origin.
But that's the problem:Even pc gamers at that time knew about FF and Dragon quest, while few ever heard of Ultima.I mean, the source you are giving of a german magazine(so, 1 country in europe) of 2000.Second, and most importantly, if the game was that influential, anyone would hear about it, even people that played exclusively on consoles.I mean, the sims(Maxis was the dev) was originally PC only, but who hasn't heard about it?
And even in forums, not a lot of people knows what Ultima is, let alone the casual gamer.But nowadays?Who wasn't heard about FF or DQ?
And that's the point.Ultima may have been a bit iconic back then, specially Ultima 4, but it was always a niche franchise, that didn't manage to make RPGs popular. Like I have said previously: Pong is considered the "first" videogame and Atari the creator of the industry.But that's not true, tecnically speaking.There were other comercial games before it, and companies that tried to varrying success, but they never actually became popular. Same with Ultima.It was FF and Dragon quest that actually made the genre popular.
Hell, the stamples of the genre, such as Lvl, were created with those franchises. Don't know if they created the concept of a party fighting in a turn based space, but they are also the ones responsible for making it popular.GTA 3 is the one usually credited for creating the open world genre, but actually the first open world game was a japanese PS1 game that almost no one knows about called mizzurna falls.Does it mean that GTA 3 doesn't deserve the credit it gets? Hell no.
So yeah, making it popular is more important than actually just comming up with the idea, because the actual implementation of the idea in a way that actually blows people mind, leaving a legacy that will be remembered for decades to come, is what changes the industry.