Ah, so they kept that too. See, I don't want to be confident in my assertions for Global, because I haven't revisited it recently enough to be - but it seems our version and theirs are the same in this front too.
That's the augment cap of 3 at play. Any item can have up to 6 affixes and can get up to 3 augments, depending on how many affixes it came with. So 0-3 affixes means 3 augments, 4 affixes means 2 augments, and so forth.
One could lift this limitation for your suggestion, letting whites with no affixes get 6 augments; it just wouldn't work for higher grades, as they already come with a few affixes of their own. That's what I meant here:
So it couldn't be, for example, +4 [augments] to Legendary across the board, unless you made all Legendaries only come with 2 affixes
Also keep in mind that Uniques are a completely different bag. Some Unique affixes may have multiple lines of effects and still count as 1 affix, affecting how many augments you can actually do.
Remnants, for example, have 6 effect rows and may look like they're full, but those are still 1 affix - which allows for 3 more augments.