Nytmare
David Jose
Let me be a little controversial. If Player A considers it a slap in the face for Player B to start at the same level... start looking very closely at Player A to decide if they are worth keeping. That is not the kind of attitude you want to encourage in a cooperative social game.
I think that a lot of it has to do with when you started playing, and who taught you how to play. From 1980 till about 2001(ish?) the overwhelming majority of D&D players and groups that I met considered it one of the most cardinal of sins to simply "create" a character that was not 1st level. That's from conventions, colleges, summer camps, elementary, middle, and high schools across at least 9 or 10 states, and that was simply just how it was done. The only way you'd start in a new game with a character above first level is if the DM allowed you to bring a leveled character from somebody else's game.
It wasn't until we were pretty much knee deep into 3rd Edition that I noticed that tide of public opinion changing.
[TANGENT!] When I was in middle school, we had a D&D game that was run by one of the Boy Scout leaders in the area. Most of the kids playing felt pretty cheated because one of the other kids would drag his character off to go play in a different D&D game over holiday breaks and he quickly rocketed ahead of the rest of us ability wise. But, thems was the rules as we understood them, and it was just something we dealt with. Eventually he started coming back sporting all kinds of magical trinkets and I think the Wand of Orcus or something, so the DM talked to the parents and called the cousin who had (supposedly) been running these holiday D&D games. He (of course) found out that the kid was lying, so we spent a Saturday afternoon putting the character through D&D court, and locking him up in D&D jail where, I'm assuming, he's still sitting.