And Mr. Gygax also moved away from the high lethality of his games by starting his players at 3rd level. I don't know from experience, but my understanding that what Mr. Gygax played at his table was considerably different-- and much higher-powered-- than what he wrote in his rulebooks.
The 1e DMG actually does recommend starting at higher than 1st level if it's not the player's first character, and, in some situations, even if it is. Gary thinks that a new player's first experience of D&D ideally should be at level one, alongside other beginners.
As a general rule the greatest thrill for any neophyte player will be the first adventure, when he or she doesn’t have any real idea of what is happening, how powerful any encountered monster is, or what rewards will be gained from the adventure. This assumes survival, and you should gear your dungeon to accommodate 1st level players. If your campaign has a mixture of experienced and inexperienced players, you should arrange for the two groups to adventure separately, possibly in separate dungeons, at first. Allow the novice players to learn for themselves, and give experienced players tougher situations to face, for they already understand most of what is happening - quite unlike true 1st level adventurers of the would-be sort, were such persons actually to exist.
If you have an existing campaign, with the majority of the players being already above 1st level, it might be better to allow the few newcomers to begin at 2nd level or even 3rd or 4th in order to give them a survival chance when the group sets off for some lower dungeon level. I do not personally favor granting unearned experience level(s) except in extreme circumstances such as just mentioned, for it tends to rob the new player of the real enjoyment he or she would normally feel upon actually gaining levels of experience by dint of cleverness, risk, and hard fighting.
- page 12
Experienced players without existing characters should generally be brought into the campaign at a level roughly equal to the average of that of the other player characters. If the average is 4th level, far example, an "average" die or d4 + 1 can be rolled to find a level between 2 and 5. This actually works well even if the average experience level of the campaign is 5th, 6th, 7th, or even 8th, especially when the "averaging" die is used. If the experience level is above 8th, you will wish to start such newcomers out at 4th or higher level. After all, they are not missing out on anything, as they have already played beginning character roles elsewhere
- page 111