During a discussion of the relative power of magic-users, the old wives' tale (old gamers' tale?) of the weak, helpless 1st level magic-user came up. Not in a bad way, since this was the ODD74 forum and therefore pro-old school. The idea is that old school players are willing to play the frail magic-user in exchange for the delayed satisfaction of becoming enormously powerful later on.
But, of course, the 1st level magic-user isn't really frail. In Men & Magic, M-Us, Clerics, and all hirelings, including heavily-armored mercenaries, have 1 standard d6 for hit points. All have the same odds of surviving a deadly blow, and all have the same odds of hitting an opponent. They can use daggers, which means they can use thrown daggers. There's also no restriction on using torches or flaming oil. There may be a restriction on armor or other weapons, depending on how you interpret the original text, but all weapons do 1 die of damage, and at worst putting on armor just removes spell-casting ability. So, a 1st level medium is no more frail than any other typical human.
But mediums are weaker than 1st level fighters (veterans,) right? Just barely. A 1st level fighter (veteran) gets +1 hit point, but that's it. They have the same chances of scoring a deadly hit as a medium. Because they can use ranged weapons or polearms, they have some advantages, but not many. Most of the benefits of the fighter class come from rapid increase in hit die/combat ability and the ability to use magic weapons and armor.
Are humans in general frail, then? Most ordinary wildlife is in the 1 hit die range or less, and most wildlife can be kept at bay by fire, or scared off by large groups. So, most humans stick around other humans, for protection, and build fires at night. A fall off a cliff, or getting caught in a burning building, could be deadly, but that's why people try to avoid those things, right? The only thing in the natural world that's really too much for humans to handle is a catastrophe or a large predator or pack of predators. But these are pretty deadly even for high-level fighters. This is why people in real life try to prep where possible and set up defenses, dealing with the horrible as best as they can when it can't be escaped.
Having established that a medium is no worse off, in mundane terms, than any other human, we have to consider magic. A medium has one spell. What some people seem to focus on is the number one, which is so horribly low, in their eyes; but what they should focus on is the word "spell". No other ordinary human has spells; even clerics don't get spells at 1st level. So a medium is not a weakling, but an ordinary human being with a one-shot extraordinary power. One time per adventure, the medium can avoid or eliminate an obstacle. If the spell selected is Charm Person and it is used on the right target, the medium winds up with an effective boost in power. And if the medium can find or buy scrolls (or, under the Holmes rules, make scrolls,) the character effectively does away with that one spell limitation.
The problem, as I see it, is that too many people focus on what they don't have yet, or what other people have that they do not. They aren't taking into account what they can do, so they denigrate their abilities. But envy is never a viable basis for short-term planning, or for game design. There will always be someone better off than you, or somebody with an ability you don't have. Even if you redesign magic-users to have at-will zap powers at 1st level, there will still be powers they don't have.