Fair point on the website. I kick myself for not having thought of it and checked.
The reason the Oracle doesn't have the same alignment restrictions as the other classes I reiterate: they don't have to worship a deity to cast spells.
Clerics don't have to worship a deity either. The class is
written largely assuming they do, but then there's this little detail in the section on Domains:
Pathfinder Cleric Rules said:
If a cleric is not devoted to a particular deity, she still selects two domains to represent her spiritual inclinations and abilities (subject to GM approval). The restriction on alignment domains still applies.
That's how it's been since before 3rd Edition, if you replace "Domains" above with "Spheres" for 2nd- and nothing at all for previous editions, since Clerics just had their own spell list back then with no ifs, ands, buts, or extensions.
They cast them innately. The source of their power can be non-aligned. It can be completely made up. You can be a Lawful Good Oracle and create a character that draws their divine power from the Negative Energy Plane if you so choose. And cast evil spells, but roleplay that you feel badly about doing it.
There is potential debate about whether the Negative Energy Plane really is Evil-aligned, but I won't start that up here. You are correct that the Oracle has that flavor, though this alone does not mean that powers granting Good-aligned spells would grant them to an Evil character. It is an interesting direction to explore, but it breaks all precedent to suggest that aligned Divine spells can be cast by opposed-aligned characters.
And it's one of the few classes you can make an evil healer that is as effective as a cleric with. You can make an evil Life Oracle that works for an evil party. There are not alignment restrictions on the oracle or where his power comes from.
I've seen this example used before and it always begs me to point out: Healing spells are not aligned, either Good or Evil, and they never have been except when GMs house-rule it. I see no contradiction whatsoever in an Evil-aligned Oracle of Life- nor would I see a contradiction in an Evil-aligned
Cleric of Healing- as long as there's a Neutral or Evil god who grants that Domain, it's all good (so to speak).
The thing that makes an Evil Oracle who's a good healer work is that Evil Oracles are allowed to pick the "Cure" spells as added to their spells-known list, above the "Inflict" ones, if they want to. And this, too, is not inconsistent with older versions of priests and Divine spellcasting; the whole notion that only Good-aligned Clerics can spontaneously cast Cures (and Evil can only spontaneously cast Inflicts) has only been around since 3rd Edition- before then there was no such rule or conflict.