I can see both points, but the bolded part I think hits the difference in preferences. For example, I tend to agree with Hemlock on this for the same reasons he gave. But obviously Seule looks at it differently, and has different opinions on what "good" is. From my interpretation, in order to be "good", a PC has to have the higher/highest numerical bonus in a particular aspect, especially better than other party members.
Also bear in mind that in 5E, as opposed to other games like e.g. Shadowrun, there are aspects which have no numerical bonus associated with them at all. You can always pick those shticks regardless of what you roll (although RP considerations like low Int might conceivably restrict you from choosing some of them).
Choose one or more of the following:
The Supercharger: the guy who kicks other characters into overdrive with Bless/Haste/Warding Bond/Polymorph/Enhance Ability.
The Healer: the guy who keeps everybody uncursed, not turned to stone, alive, and at full HP.
The Arcanist: the guy who makes sure the party always has a safe place to rest, can always teleport to adventure and/or to safety, can decipher languages, etc.
The Summoner: the guy who spies or fights by proxy using conjured elementals, animals, familiars, and/or Chainlock invocations.
I believe these are the main non-numerical aspects I've seen. They are pretty broad, and ideally you'd
like to always have one (or more!) of each in a given party, but you can't because there aren't enough PCs (in a four- or five-man party) to fill these roles and other, more stat-dependent roles like "ranged specialist" or "crowd control." So even if you roll up an array of all 3s, make a character that fills some or all of these aspects and you'll be making a valuable contribution, if you can bring yourself to roleplay a barely-sentient vegetable.
For example, I give you
JoeBob the Clerical Savant: senile, 120-year-old adventurer on his last legs, can barely think--but old reflexes die hard!
NG Human Trickery Cleric 7
Str 3 Dex 3 Con 3 Int 3 Wis 3 Cha 3 HP 24
Feats: Tough, Lucky
Skills: Stealthy, Perception, [some others]
JoeBob is barely sentient any more and will probably die any second now. He can barely even communicate, but he still (barely) remembers some old adventuring tricks which he can still use if somebody asks him. For example, if you tell him, "Hey, JoeBob, let's you and me play Mama Bear, okay?" he will twitch his fingers and cast Warding Bond on you, and then Polymorph himself into a T-Rex who follows you around trying to keep you safe via the Warding Bond and his loads of extra HP. If you tell him, "Hey, JoeBob, I need to be sneaky," he will bless you with the tricker's blessing (advantage), and if you ask him to come with you he will also cast Pass Without Trace and follow you around. (His total Stealth bonus under such conditions is +9, which is still respectable.)
He also has triggers for casting Bless, Dodging, casting Dispel Magic/Greater Restoration, healing wounds, and running away as fast as he can.
He shows little initiative and won't generally do anything outside of these predefined parameters (will
not innovate tactically), except drool and stammer. Nevertheless he is surprisingly stringy and tough for such a frail-looking old man, and fate has so far smiled on him enough to keep him alive.