Uneven is not inherently unfair. That's just your personal view of the results. The results of of the fair rolling method are inherently uneven and that's where it stops.
1. Since rolling is an equal method, the results being based on the principles of equality(justice doesn't apply) means that the results are fair.
2. Nothing unkind, inconsiderate or unreasonable about rolling. It's a fair method. If you don't like it, don't use it.
3. It follows the rules of the game, so number 3 doesn't apply, either.
This argument that the character you get is fair because you all had equal use of a method that produces variable results, sometimes widely variable in numbers you will be forced to feel the consequences of in every game you play is a patently ridiculous one.
Just try pulling that stuff on MMO players when they log on and forcing them to play the character. You'd lose money so fast your company would collapse in a week.
It's like saying that as everyone has an equal chance to be born into a rich family, and as everyone is born to a human mother, that social inequality is 'fair'. It is like saying that as everyone has (on a population scale) a statistically equal chance of being born with a disability, so it is 'fair' that some have one.
What utter tosh.
It's the numbers you end up with that matter - not the method of determining who will be disadvantaged and who advantaged by RNG.
"Sorry bud, but as you all had an equal chance of very high or low numbers, the other player gets to have a more powerful character than you at the start of the game, and you cannot play that MAD character class you wanted to as they will be far too weak and a liability on party survival. You can instead play
this character class which will at least be something other than useless. Tough luck by the way..."
The fact is a lot of DMs faced with the above scenario fudge the issue out of pity and allow re-rolls, and are equally forced to accept multiple 18's when they come up - even on a re-roll, also meaning that the average roller who didn't quite qualify for the pity-re-roll had half the statistical chance to get a high stat character. Once again, a commonly enough encountered unfair consequence of rolling stats.
The fact is, point buy or the standard array always allow you to play an effective member of a class -
always. Random rolling doesn't, and can force you to play a class you didn't want to so as not to be useless. Or, as I have also seen many times, encourage players to suicide their character to get a re-roll.
Random stat generation is unfair, and people can be quite creative in getting around it, because they feel they have to. It should not be necessary, and everyone should have an equal start.
As for the comment about 3rd edition you made. I encourage you to revisit the numbers and rethink - the issue should be self-evident, so I am not going to get into it further.