This has already been discussed.
"Magic" is the keyword here. I see people keep going back to this like it's a firm justification for the argument when it's not.
I fail to see how "it's magic" answers the question, "is that an unacceptable limitation on narrative space?"
Especially considering there are non-magical explosive effects that, likewise, automatically deal damage even on a missed attack roll, and if we're being sticklers for simulation it is way more likely for a single round of ranged ammunition to go wildly off-target and completely fail to affect a target than it is for 6 seconds of life-and-death melee to fail to affect the participants.
Is "you can't completely avoid losing hit points," not limiting narrative space? It's true regardless of whether you try to apply it to a targeted explosive burst or being nose-to-nose locked in melee with someone trying to murder you. The real question is: "Why does being locked in a deadly melee engagement causing automatic HP loss break down verisimilitude so much worse than a targeted explosion causing automatic HP loss?"
The answer seems to keep coming back, "Targeted explosions are mainly a wizard thing and anything is OK if a wizard does it because wizards should always be cooler than grogs."
How about this?
Let's use a molotov cocktail. Now, which do you think is going to do more damage?
A: I throw it 2 feet away from you and it shatters.
B: I hit you with it directly and it shatters as it hits your body.
Ironically, if you hit someone with a molotov cocktail directly anywhere but on the skull or a hard joint (knee, elbow) it probably won't shatter. It'll deal bludgeoning damage like any other thrown bottle. The problem will arise once it shatters at their feet, but if you hit them in the chest, abdomen, or on muscle it will be bouncing - away - from them when it hits and likely have momentum carrying the contents away from them as well. Of course, if they happen to be armored the likelihood of shattering on impact goes way up - as their armor actually makes it much easier to "score a hit" with that particular weapon.
The proper way to try and set someone on fire with a thrown molotov cocktail is to throw it directly at hard ground in front of someone's feet so the gasoline splashes up onto their body while catching fire. You can't count on the fuse or seal reliably enough to use it as a hurled explosive. They are typically best for smoke screens, property damage, and burning out people in enclosed spaces like vehicles or smaller rooms.
- Marty Lund