Dude, seriously, there's no nice way to put this, but I'll try.
You're arguing against a spell that exists only to inhibit one (1) material in the game. You're proposing that this spell, something that requires concentration and mana, or time spent brewing, should be partially ineffective against this sole material it was designed to protect against. It existed before racial weaknesses were even put into the game for the purpose it has now, and racial weaknesses were put in blatantly knowing this spell existed and it was even buffed instead of nerfed (to include steel). This material it protects against is not unique, and it is not overpowered - in fact its most powerful form breaks against the most average of armors, including tanso steel. What is the point of the lines of code this spell takes up, if it doesn't affect in any worthwhile measure the only material it is designed to affect? It does scale with the level of the spell - jman warlocks are not immune to your level 30+ iron weapon, anyway. It scales as you get it to reduce damage until 50, where you become immune. Does this crusade sound as idiotic to you now as it does the rest of us, yet?
No? Well, keep reading. You will catch up to the rest of the kids eventually.
You're bringing up other defensive spells now. You're also talking about sprite and elf sorcs being able to sleep with charm person. You whined so hard about straw men earlier, and start popping them down left and right here to sound...I dunno, less fail than you really are. Sprites and elves can sleep with 1 charm, and this fact means that their stats are not inherently worse for said class than other races? Because sprite swashbucklers have adequate HPs to or STR to be even remotely worth the effort in rolling one, and won't be deflected off of unenchanted adamantite? Another straw man, too - who said elves are bad in the front row? Anyone can play anything with enough decent gear and mass preparation (and 50 vials of word of recall/spam retreat x50, amirite lolol).
The point of the matter is the only thing this does is keep you from doing 150% damage to races with the weakness to iron. That is the only purpose to this spell. In any and every other circumstance, if doing 150% damage with iron is not possible because you are fighting a different race, there are more than half a dozen other materials better suited that are plentiful that everyone can, will, and already do use - making this spell useless in circumstances other than racial weaknesses, or fighting guards (and, #&*$ guards and NPC wars, so I'm okay with that part, too.)
You're being an idiot for using more strawmen out of one side of your mouth as you complain about them from the other, on top of already being an idiot for making a plainly foolish case against a spell that exists only to do what it is doing right now. It's plain and simple: this spell only exists to stop iron. There is absolutely not one reason anyone can conjure that argues against its current nature of increasing damage resistance as you level, until 50 where you hit immunity. It exists to do exactly what you're arguing it shouldn't be able to do. If you are going against someone with ironguard, tell you what, i'll make it easy for you:
Code:
* Heavy Armor -- adamantite, diamond, gemstone, iron, obsidian, platinum,
steel, stone, tanso steel, cold iron, jade
* Light Armor -- amber, brass, bronze, china, clay, copper, crystal,
flesh, food, glass, gold, ice, ivory, leather, meat, mithril, pearl,
plant, scale, silver, supernatural, wood, dragonscale
* Clothing -- cloth, energy, feather, flame, fur, ink, paper, parchment,
rubber, silk, suede, vellum, water
There's a list to help you plan one of the other materials you can use in your next master-strategy gank. Get out of here before you hurt yourself, sunshine.