Because poison was so very lethal in OD&D, 1E, and 2E, and if the DM had really wanted Tucker's Kobolds to kill the party, it would have been simple enough:
DM:
A squadron of kobolds with readied hand crossbows with poisoned bolts appears. They have Surprise.
They all fire. 10 incoming poisoned bolts. 5 hit the fighter. Roll five saves versus Poison.
(fighter fails 2 of them, dies.)
That is an example of exactly why 'Tucker's Kobolds' don't ring true to me.
I've adventured as a 12th level character in 1st edition AD&D. A kobold with a hand crossbow even with surprise probably would need a 20 to hit you AC, and any M-U's would probably have stoneskin and/or protection from normal missiles up. So the expected result of 10 incoming poisoned bolts is zero hits. And a 12th level fighter with minimal magical protection would probably fail a saving throw versus poison only about 1 time in 5. So, each character would expect to be able to soak up about 100 poisoned crossbow bolts before dying (which for all but the most expensive insinuative poisons would take more than one round). Long before that would happen, clerics would be casting 'slow poison' on everyone (12 hour duration at this level), reviving newly dead characters to await treatment and protecting everyone else - and they'd do this and be ready for this precisely because they were used to poison being so deadly in 1st edition. They wouldn't have survived to 12th level if they weren't prepared to handle the whole party being poisoned by venomous hydras or teams of leveled drow commandos or what not.
Moreover, the chance of the kobolds achieving surprise wouldn't be that good anyway. Some waves would just die outright.
Tucker's Kobolds were not played in this spirit.
No, they certainly weren't. Because if they'd even been played in that fair of a spirit, the kobolds would have gone down hard and we'd never even have heard about them. 'Tucker's Kobolds' were played in a spirit far less fair, if perhaps somewhat less bloody minded, than your example, else they didn't have a chance of threatening a party of 12th level characters.
I agree with the point of Moore's editorial. Moore was trying to suggest that at higher levels, for the game to be challenging, the DM had to be creative. He was trying to suggest that high levels of challenge could be maintained through the upper levels by putting the characters at a tactical disadvantage. But his example is I think a very unfortunate one, because as someone whose played at that level I can't help but read the examples and think, 'That's only challenging because the DM was just cheating, fudging, and meta-gaming left and right, or else he's running a hyper low magic game where noone has magic armor, bags of holding, rings of protection, or anything, or else your whole party is a bunch of inexperienced novices that were just given high level characters rather than earning them, or some of all of that.'
Because in actual play, the M-U would be using telekinesis or gusts of wind to push those broom pushed piles of debris back over the kobolds, would be collapsing tunnels with transmute rock to mud and conjured earth elementals, would be killing off whole armies of kobolds with walls of fire, flash freezing rooms with cone of cold, knocking off dozens of them with sleep, frying narrow tunnels with lightning bolts, siccing invisible stalkers on the poor things, dropping cloud kills on them and so forth. One insect plague would keep the whole bunch of them busy for a very long time. Meanwhile, the fighters would need roughly a 2 to hit the archers through an arrow slit, while the kobolds would need roughly a 20 to hit. Kobolds would drop like flies and do virtually no damage.
So how did the DM make it work? Well, I suspect he 'cheated'. Those 'steel tipped bolts' conferred a special +3 bonus to hit the first time they were fired (afterwards they became blunt, naturally). The kobold archers probably had other special bonuses (they were all specialized in their weapon, they all had 16 DEX, they all gained a +2 tactical bonus to hit, or whatever). The kobolds archers could do a special 'split fire move' that violated the normal rules to avoid getting shot at. Every thing that the characters did was always interpretted in the worst possible light, failing to work or even back firing. Areas of effect were always assumed to catch the minimal number of kobolds. Everything the kobolds did was alwayer interpreted in the best possible light. Countermeasures to spells were sometimes invented on the fly. Kobold losses were always replaced at an exagerrated rate. Morale was never checked no matter how many scores or dozens of kobolds met Kurtulmak.
Meanwhile, the players are using tactics that suggest, among other things, that no one has a bag of holding - much less anything unusually good.
I'm not even sure we can trust Moore as a reliable narrator. For all I know he's exagerrating the situation to make a point, but I suspect based on what TSR actually published in 'Axe of the Dwarvish Lords' that he isn't. I'm glad that they had fun, but it reminds me more of when some of my fellow players waxed nostalgically on terrible DMs with pet DM 'player characters' that repeatedly tormented the party and was essentially immune to any counter attack. They had fun too, but they also probably wouldn't have chosen to go back to that environment.