It takes a certain degree of maturity to handle rolling for stats. (Or maybe fatalism.) Some players are happy to roll once and keep whatever the dice give them. Others are like gambling addicts and it doesn't feel "right" until they give a very high array of stats.
I think it may be worth noting that both of your examples are of folks wanting to roll for stats...
On the notion of character clones.
I'm rather baffled by this actually. Ok, Standard Array means that every character has the same 6 stats, arranged differently. And, to be fair, similar classes will have pretty similar stats. Not exact, mind you, but probably close.
But, so what? Two fighters, for example, are identical in all other ways and that doesn't seem to cause any issues. Same HP, same saving throws, and all characters with the same stats have identical skill bonuses. Why doesn't that blow your mind?
Immersions are very personal things. Immersion can survive the most profound abstractions, inconsistencies, and disconnects, but be 'shattered' by one little thing being slightly off. What's different? The personal suspension of disbelief being shattered, nothing else.
It may seem like a strong reason for a preference to the person experiencing it, but it can't always be catered to in detail - some compromise is generally necessary, though groups can winnow their way to some sort of consensus through attrition over the years...
I guess I just have a real problem with the level of cherry picking people seem to do when justifying their preference.
Personal preferences are just that, personal, that's all the justification they should need.
So here's the thing. Even high stats are not a problem. The game is very flexible and can easily handle 6 PCs with straight 18s if you wanted to run a game like that.
To be fair, it gives the DM a lot of latitude to be flexible...
High stats can't break the game.
But, that's not really the issue. The issue is 1 PC with straight 18's and 4 PC's with average stats, and 1 PC with toilet stats. And no, the game does not particularly handle that very well.
IMX, a high-stat PC or two can tend to 'fix' the game at very low level. Early on in AL (I think it was technically still Encounters, even), with array characters and preliminary encounter design in HotDQ, 5e skewed weirdly lethal at 1st level, but when I used random generation and some post-racial 18's and 20s slipped in, it got significantly easier on the party. Even the PCs that got comparatively poor stats (not a lot worse than array) would tend to survive, thanks to the party being more consistent in combat.
Of course, at higher level, the game has to expect high primary stats, because of ASIs. So it should even out, then, too.
I'm afraid low stats break the game worse than high.
Thing is, and let's be honest, 2 of those characters (numbers 2 and 4) will almost never hit the table. They just won't in my experience. Or, if they do, they quickly commit suicide by orc.
The inherent fairness of random generation absolutely requires that if you roll crap, you play it in good faith for the whole campaign. Undermining that does the method a severe disservice. (I mean, if you make very high stats re-roll as well as relatively poor, maybe... but I've never heard of such a thing.)
It's not the Oberoni at all. I'm not saying that it's not a problem if you can fix it. I'm saying that it's not a mechanical problem, which it isn't. If it were a mechanical problem, it would affect everyone.
It is, and it does, it just doesn't manifest in the same way for everyone, and most of us have been dealing with the same or similar problems for so long that it's not really a matter of 'compensating' anymore, it's business-as-usual, and trying to cope with an effective mechanical solution would feel like more of an adjustment than continuing to do so....
...yeah, that's 'Oberoni,' in a way, but mainly it's just D&D.
The game has to be adjusted for all kinds of personal reasons.
It's part of the brilliance of not just asserting DM Empowerment (technically 3.x 'Rule 0' was totally empowering), that it also laid the groundwork for it by inserting the DM's judgement into the mechanics at the most basic level, writing in natural language to, again, require frequent rulings, and assuming so little (no magic items, no system mastery, no feats or MCing, etc) that customizing the game to even fairly typical preferences necessarily means re-balancing it to suit.