How about some arguments to back that up? Why is balance necessary for backgrounds? Why needs a former professional basket weaver to be as useful as a sailor in a naval campaign?
And if you strife for balance, lets remove all character customization. Thats prefect balance.
I think it depends on how you define balance.
To me, balance means that the players have to make decisions where no course of action is obviously better than another - their choices are
balanced. (It's important to note that there must be a difference in the outcome - otherwise there's no decision to be made.)
If you want players to make meaningful decisions about their backgrounds during character creation - which is not necessary to play the game - then you'll want to balance the choices the players make.
That's my argument for balance.
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The way I run my D&D hack, there's a limited list of skills. Backgrounds, physical or personality traits, and training skills are pretty open-ended. Backgrounds are limited by the setting (raised in the only civilized city; refugee from a ruined city or town/village; savage raised by barbarians or something more exotic - like wolves; and stranger in a strange land, which covers earth-men in rocket ships and characters out-of-time). Training skills (apprentice, student, guild-trained, manual labourer) tie you to someone else.
Racial and class skills are more codified and detailed.
A note about racial skills: humans have "social class" and the other races have skills that sound a lot better: elves who can see forever, dwarves who can talk to stone, Eladrin who can remember past lives (like 4 skills in one). Running the game, though, a human PC who took "Middle Class" as his racial skill got a lot more out of it than the dwarf who could talk to stone. (Most of that is probably the setting - human-centric.)
There isn't a list of "DCs" or things you can do with the skills. You state your action and, if the skill is obviously associated to your action, you get a bonus to your roll (or two bonus dice, which is what I'm using now). If it's loosely associated, you get a smaller bonus (or one bonus die).
This is nice because you don't get players saying, "I use Bluff on him"; you get the player acting out the bluff and then they pull out a bonus die or two (depending on the bluff) for being Trained in the Thieves Guild. It's bad because players feel too much pressure to justify the bonus skill dice. (The guidelines to getting bonus dice are supposed to be relaxed so that players don't feel too much pressure to justify them, but obviously that's not the case; oh well.)