While alignments as proposed by Gygax are thoroughly stupid, the concept of alignment could perhaps be a useful one, albeit in a manner fairly unrelated to the most common six-axis view of the system.
If you asked me, in real life, what my alignment is, I'd probably tell you my political affiliations. I'm a socialist, and am aligned with Canada's socialist party, the NDP. Someone else might be strongly influenced by their faith - they're aligned with the Catholic Church, say, or Sunni Islam.
This means that, on a broad range of issues, our ideas line up - they align. And this is useful and gameable information. If you're running an NPC in modern Canada, and you know they're NDP-aligned, that tells you a lot about them. Any issue that you're not sure how the NPC feels about, you can fall back on their alignment, and say that there's their opinion.
This needn't be as grandiose as supporting warring dynasties like being aligned with the House of Lancaster or York. Peasants in a village could be aligned with the Reeve or the Lord of the Manor, or perhaps the outlaws in the woods. Villagers could be aligned with a Guild, or the Mayor, or the Bishop.
Like in real life, people could be aligned with more than one faction. Someone could be aligned with the Catholic Church, the local Reeve, and the King, in that order. So, if you don't know how they feel about something, you can default to one of those positions as a shortcut.
So, an alignment line on an NPC sheet could look like:
Denoting that the NPC is Catholic and strongly aligned with the Pope and his beliefs. On matters that don't include the Pope's opinion (say, whether the village should plant more beans next year), the NPC will generally side with the Reeve. And on matters that involve neither (France is an enemy), they'll side with the King.