Many of the posters who want fighters to to have spellcaster-esque limited resources and 4e powers.
Ah, you mean like the barbarian's
rage spell from the 3E PHB.
Other than keywords, exploits are identical to spells.
Other than keywords, an Entangle spell in 3E is identical to a Tanglefoot bag. Other than keywords, an Evard's Black Tentacle spell in 3E is identical to a fighter grabbing you. But nothing very interesting follows from that, given that keywords are the principle means that 3E and 4e use to mediate between mechanics and fiction.
If you removed the names, keywords, and flavour from 4e powers, there would be a lot of overlap and it would be hard to tell a spell from a prayer from an exploit.
If you removed the names, keywords and flavour from AD&D spells and AD&D combat, there would be lot of overlap and it would be hard to tell things apart - it would all just be rolling dice and calling out numbers! I don't think that proves very much, other than that names, keywords and flavour are pretty integral to roleplaying mechanics. (Especially in D&D, which is mechanically based on long lists of effects (be they weapons, spells, monsters, etc) which, at themost basic mechanical level are based primarily around tweaking the numbers.)
As long as you entirely ignore what is going on in the world exploits are identical to some spells. Which is like saying that as long as you entirely ignore the order of the letters, Finnegan's Wake is identical to Twilight is identical to Lord of the Rings is identical to the 1e DMG. Because they are both made up of letters and spaces.
This too.
MBut if they can only use it once a fight or per day for no reason other than "because spell can only be used 1/day too" then it's a spell, just not a magical one.
Do we have to do this in every thread?
The 1/enc and 1/day limits don't operate in the fiction. They operate at the metagame level ("gamist", in [MENTION=59096]thecasualoblivion[/MENTION]'s terms). As [MENTION=87792]Neonchameleon[/MENTION] said, it's a pacing mechanic.
We all get it that you don't like metagame mechanics. But it doesn't help to communicate that when you describe the mechanics in a way which no one who actually likes and uses them agrees with.
it's a description of how much [mana/stamina/mojo/etc.] your character has
That's one reading. It's not the most natural - I prefer the metagame reading - but whatever floats your boat!
Imagine a 3E barbarian who starts the day, gets surprised by a fireball, fails his/her save and is down to single digit hit points. And still has all his/her rage left for the day. Is s/he tired (low hit points) or pumped (full rages)? However you answer that question, I suggest you use the same method for answering the question about a 4e fighter high on encounters but low on dailies.
Or alternatively, appreciate that these are really metagame mechanics.
The reason that fighter powers are spells is not because fighters have a use-limiting mechanic, but because they have the same one as spells.
D&D has a long tradition of using the same mechanical structure for diffrent fictional elements. In AD&D, for example, a cleric's saving throws represent prayer and divine grace, a thief's deftness and subtlety, and a fighter's sheer toughness - yet they all use the same mechanic.
3E is the only version of D&D to insist that everything which is different in the fiction be different in the mechanics, and even then it doesn't carry through on the promise: barbarian rage is mechanically the same as spell use, and the distinction between EX, SU and SP abilities is in some cases explicabe only by reference to flavour and keywords.