I'm confused, how is this unrealistic? the burst of fire is hot enough and brief enough to melt metal and burn flesh without setting it on fire. Even with a save a character (barring a special ability, spell, etc. that negates it) takes damage from a fireball.
Interesting, so to you it's not unrealistic. Gold that has a melting point of 1947.52 °F will melt when a fireball ignites in a room for less than a second, but a creature's hair which starts to burn at about 451 °F will not even be affected when it fails its save. And a creature can't catch on fire when it fails a save.
Yeah, they take damage. There is no dispute there. In 3.x creatures inside the burst of a fireball take damage. It also melts gold. But it doesn't and cannot set the creature on fire, because???? That would be unrealistic?
See, when you start using "realism" as the measure of what happens you end up with these weird situations. The right answer to the above "WHY" is that the designers decided that damage was well enough for design work, and didn't add anything else in. Realism had absolutely nothing to do with their decision. The bounds of the effect that they wanted to provide was the only consideration in their design. They're not trying to simulate anything realistic. They are giving you a particular self-contained effect. That is the only "why" for why certain things, like gold, melt but the creature does not catch on fire.
So when questions of "why" come up about 4e, I refer to the same situation. The intent of the designers is not to inject realism, it is to design rules that provide the specific desired effect. In the case of fireball, an area of effect spell that does fire damage to creatures and, if desired by the DM and players, objects. Realism, verisimilitude, plausibility, whatever you want to call it has nothing to do with it, and never has in any edition of the game.
