Agreed. A lot of detail in spell descriptions seems like some earlier groups' adventures, and their GMs' rulings, turned into something rigid for everyone. Rulings not rules!
The hilarious thing is that 4e HAS A RULE FOR THIS, it just isn't called out in the Fireball spell, why should it be? Objects can be attacked by spells and the DM is perfectly well in his rights to run an attack on everything in the zone of the spell. It works just like any other attack, each object has hit points, etc all perfectly straightforward.
The problem here isn't the lack of a rule to cover burning things with a Fireball, it is the expectation that this rule will be called out in every single place that might use it. 4e assumes you know the rules. They are very regular and have only limited exceptions that are caused by the specific situation. This comes up in other places too.
For example: A guy a while back told me that the 4e Flametongue was 'flavorless and dull'. I compared it to the 1e flametongue. They do virtually EXACTLY the same thing. The difference is the 1e version has 2 long paragraphs that try to explain all the rules surrounding a flaming sword, that it casts light, burns certain creatures, starts fires, etc. The 4e version invokes the fire keyword and describes the sword as bursting into flame when activated. Presumably you're supposed to know that fires burn things and that they shed light (admittedly this could have been called out as a property perhaps, but still fires make light, not rocket science). The 'burns certain creatures' part of course is covered by other rules (Vulnerability) and the fire keyword. Clearly if you simply imagine what a flaming sword does the 4e flametongue is no different from the 1e flametongue. Yet just like with the Fireball apparently things just MUST be spelled out in nauseating detail. I dunno, I don't like to be critical but it feels like people's creativity is broken and needs a cast or something? I don't get it...
EDIT: Oh, and Pemerton, OF COURSE D&D is just the compiled rulings of vast numbers of Gygax and Arneson, and Rob Kuntz's (and then other people of course, but probably mainly them) games. Go read "Old Geezer" over at rpg.net if you don't believe me. In fact he's got a kickstarter up IIRC to put out a book of "playing with Gary" annecdotes. He's kind of the ultimate Grognard, but his book title is pretty clear "We just made up some




we thought would be fun". Every time they played the DM just wrote up what they did, made up new stuff for each game, etc and it just got stacked into the book pretty much. Obviously things got revised and reworked and extended, but the "Fireball shoots from your fingers and explodes when it hits something" language MOST SURELY would trace back to some very specific single instance of play sometimes in 1972-74 probably. Same with the 'expands to fill a volume' language, etc.