Now, I haven't played the PoE beta. But I've seen the attribute screens which already pretty clearly underline a problem with the game's system.
It's not about whether the stats are competitive vs. each other, or significant enough to alter your playstyle - those numbers can be easily tweaked to reach a reasonable balance.
It's just the core concept that's iffy. Basically you've got Damage Dealing stat, AoE/duration stat, HP stat, Accuracy stat, and so on. These could really be named anything and the description text could say anything, in their core they're still just that. Which is kinda ok from a mechanic perspective, I suppose, but thematically the attributes presented don't really let you realize different character concepts you might have. Does a PoE mage with high Might really feel like a muscular dude? Or just a mage who has high damage spells? Basically the stats feel like very different things depending on which class they're given to.
D&D is simplistic and in some ways just bad, sure, but at least it tells us some things - warriors are strong and tough, and mages are smart, as a rule. Which gives a thematic background into what kind of people would pick which profession. PoE tells us that any kind of person is fit for any profession, only thing that varies is their exact combat role. ToEE implementation (the point buy side of it) was p. good all in all, you had real choices to make. The BG/IWD method was p. pointless of course.
The proper way to come up with an attribute system that doesn't feature easy dump stats, I think, would be to rather give each stat more variables that it affects, rather than reducing each to one or two universal % modifiers. You start by defining, ok we plan on having these base attributes for each character - what should they affect? Strength would affect how heavy armor you can equip (or how fast you get tired in it), how big a bow you can draw, how much HP you have, etc.. These things can be very relevant for a wizard too, actually, at least if you don't enforce strict class restrictions into what kind of armor they can equip, or give them magical blast attacks they can use at any time if they're not casting proper spells. If you want you could also have it affect some part of spellcasting too, like give a minor boost to how quickly you can cast a spell, or how good you are at keeping casting a spell when you take a hit while spellcasting. Or give wizards some self-buff spells that can turn them into serviceable fighters, so that their combat stats can matter more (yet it's still doable to just ignore those spells).
This whole Sawyer philosophy outlined in the article - everything must be simple without many modifiers so that it's easy to balance - is very obviously Dumbing Down. It may be Dumbing Down Done Right, but it's still much worse than a proper, complex RPG system. Proper balance in a game is a great thing, but you mustn't sacrifice complexity for it. You should first make a system that's properly cool and interesting, then when that's lined up, then you balance it to the best of your ability.