It changes the nature of the setting. Setting warping. You can see the many times I have written about it before on this forum. It probably doesn’t make a difference to the people watching, who just see mages.
Just talking past each other.
I am not talking about PCs, but the setting itself. In a normal distribution of ability scores, some will be sorcerers and some will be wizards. In terms of the setting, Athasians will see the two types of mages as exactly the same.
Well… she was called a sorceress. LOL. I think a lot of the resistance to sorcerers comes from the subconscious thought of “but the SMs aren’t sorcerers!”.
Anyway, having variant mages like sorcerers, dread necromancers, warmages and so on don’t really change anything. The dynamic is still defiling vs preserving… except the for the alternative power sources, which literally came in the second last product in the entire line. The vast majority of people playing DS at the time never used alterative power sources and they don’t even make sense.
As for spellbooks etc being a useful investigative tool for templars, yeah sure. So are spell components, the most common of which can be eschewed with echew material components (and I suspect this to be very widespread among wizards), and a certain ACF for wizards can obviate the need for spellbooks altogether. What I am saying is that this particular objection doesn’t seem like a big deal.
If the objection is that sorcerer is spontaneous this or that, and psion is also this and therefore its not on, I still have to wonder why. Psionics is psionics, magic is magic. A psion can learn their entire list given enough time. A sorcerer is highly restricted in the spells that they know. The differences seem quite large to me. This is also the first time I’ve seen this particular comparison.
And finally -
A pregnant woman had charm person cast on her at some time during her pregnancy. Now her teenage child just cast a spell. Its not blood, but magical pollution. Yet another reason to fear and loathe arcane spellcasters, lest their magic leave a taint on you that will ruin you children.
Even in 3E, the idea that sorcerers were really from bloodlines was ambiguous. I even posted the canon descriptive text for that upthread.