As far as obtrusiveness goes, I really don't think it would be the case for the games I hope to play. If I'm playing with a semi-high level party, consisting of corrupted wizards and wary warriors, my 0-level funnellers will likely be better shielded by the others than they would if they were "throwaway" NPCs, and definitely surrounded by a better class of combat ally!
I see this as an ongoing feature, not a bug, in the rules.
Some of the most fun I ever had playing an RPG is when I had a vulnerable character going "above" his level, and devising ways to survive.
Not saying it's a bug.
But if I'm running a game of 4th level PCs and one of them dies, I'm not going to make a big deal out of it if the player doesn't want to start over again at Level 0.
If a player wants to start over with three zero level PCs, I'll be fine with that too.
But I won't mandate one way over the other.
I think 0-level is a great way to start a campaign. I think it's also something fun to revisit every once in a while. But I understand where those who don't feel that way are coming from. I'll probably offer my usual -- which is start a new character at -20% current XP -- or start out with 3 0-level PCs with some sort of bennie for the character that makes it through the funnel. Magic Item. Extra Luck points to spend. That sort of thing.
So that way a player has the option to come back into the game at a reasonable power level compared to the rest of the group. But weighs that against possibly getting something really cool for a starting all over again.