I disagree. The only reason they changed it was because Dragon Quest was copyright with Dungeons and Dragons at the time.
That's a failed argument. They weren't using the "dungeons & dragons" trademark, and Enix's game Dragon Quest came long before the board game in the US, as did the change to Dragon Warrior for NES release. Total prior art victory if it ever came to court.
Anytime you can keep things the same it's better to do.
And that's the point, they didn't, and it was far too late when they did.
The real reason why they did it was indeed to keep the names the same, to save some money on the loads of logo graphics for ports and remakes as of then, not for some noble reason. I also don't like the Dragon Quest name, might as well call it Dragon RPG or Dragon Story. Not that Dragon Warrior was any better, but maybe it can be, and the fact that it already was named that way pushes it over the edge to me.
As far as the Final Fantasy argument. Even I can understand how the FF game versions matched each other, but maybe I'm just a genius that way. But for Dragon, I think Americans aren't so dumb to be incapable of distinguishing game names with the same numbering.
Just like they changed all the things in DQ8 back to correct translation.
"Correct" in this case is 100% subjective artistry. Esp. when we're talking about a translation.
For example, in literal translation vs. natural translation, I'd say that even with rom translations the latter has gained favor, and it's the better choice.