steeldragons
Steeliest of the dragons
I think it's more an entitlement issue.
Most definitely. (Which, at the risk of delving into armchair psychology, I would posit is at the root of "powergaming" as an issue, so GregK is also onto something with that.) I wouldn't be surprised if the new game introduced a new grouping of extra-planar entities called "the millenials" who are out to conquer the gaming world (and will some day succeed).

If you have a group of experienced players and/or a particular adventure/campaign idea and want to start your game at 4th...6th...10th...whatever, there is absolutely no reason you can't do that. Never has been in any edition.
I've "started" play in groups where we drew up characters of any/all levels...highest I think was the DM wanted to run the Drow series without tons of adventure/game time beforehand. So we all needed to make, I think it was (if I'm remembering the module/s correctly) 10-12th level characters out of the gate. But we were all well-experienced players at that time.
Always fun to do that, you can have a lot more creativity (since your PC has had a lot more "time" in the game world) with your backgrounds, spell choices, magic items (DM approved, of course) that you could start with, etc...
But certainly not a way to "start" the game as an introduction with new players.
For the introduction into a game for people who don't know, why on earth wouldn't they start at 1st level?...and as Zaukrie points out, even if they went with this suggestion, whatever level the game starts at is the FIRST level...so you're gonna be stuck with a 1 on your character sheet anyway.
Is this just "hatin' on the #1"? The Count will be most disapproving (Bwa-ha-ha.).
Level 0 is all well and good for people who want that flavor of startign from absolute scratch, "yes, I just walked off of my farm (probably leaving my hard working family in a lurch) and decided killing dragons would be a better way to make money."...some people like it, personally, I don't see it as being "realistic" or aiding in "immersion" in any fashion.
And, as someone just stated upthread, "I'm a pig farmer!" doesn't really get ye olde imaginative juices for a heroic fantasy game flowing...least, not for me.
Lan-"if I had this system to use I'd likely run on the veteran track"-efan
<raises goblet of fine elvin wine> "TO THE VETERANS!" <big gulp>
--SD