Or, you don't play a game that demands you set up your attributes with dice.
Why have dice if you're not going to use them?
Less facetiously, I've never bought into the attitude of "my character concept overrides everything", especially when it forces the DM to include or add things to the setting that weren't otherwise going to be there and-or that she didn't want to have there (e.g. a player insisting on playing a Dragonborn in a setting where they don't exist).
Also, I see characters as being largely representative of their population. Look around you. No two people are the same, and many of those differences come down to either genetics or random selection, over neither of which does the person being born have any control. That random element also applies to an in-game species population - some Elves are by chance going to end up stronger than others, some smarter than other, and so on; and some will have all six attributes higher than others.
What the dice tell you is are the random attributes of the member of the population that's in process of becoming your PC.
That, and I'm not worried about fine-tuning intra-character balance to nearly the extent that an array or point-buy system produces. It's just not a concern, beyond making sure the character's playable at all. I should note I don't use 3d6 in order - you've got some control over what goes where and you roll more than just 3 dice for each stat - but if your character concept needs two 16s to work* and the dice give you 18-13-13-12-10-10 then you've gotta rethink.
And if you're not willing to rethink, to me that's a red flag as to how you're going to approach the rest of the game.
* - an example is a 1e Illusionist, which requires a 15 and a 16.
