Let's be real, if you're someone similar to the second guy, imagine some other game is made after Undertale not made by Toby Fox, and it becomes popular, and at that time Undertale has become very old.

But then there's a character in that new game that looks very similar to someone from Undertale, and when people see the Undertale one, they don't recognize it as an Undertale character but instead as the character from the new game (because of not knowing about Undertale before), would you not say something atleast similar to what the first guy here said?

Like it's only natural for Yume Nikki fans (like me) to say that, especially when there's alot, and I mean, ALOT of people who recognize Uboa as Gaster instead of Uboa. And I've played Yume Nikki AFTER playing Undertale and still saying this.