Edit: obligatory explanation (thanks mods for squaring me away)…
What you see via the UI isn’t “all that exists”. Unlike Reddit, where everything is a black box, there are a lot more eyeballs who can see “under the hood”. Any instance admin, proper or rogue, gets a ton of information that users won’t normally see. The attached example demonstrates that while users will only see upvote/downvote tallies, admins can see who actually performed those actions.
Edit: To clarify, not just YOUR instance admin gets this info. This is ANY instance admin across the Fediverse.
You being a real person has value for a company beyond the specific identity you have.
Properly aggregated upvotes and downvotes are a paradise for testing and building models that then reach you not as a single entity but on the bulk. Think election campaigns that, say, take advantage of a newfound correlation between people that like cokes and the NBA and being sensitive to the rhetoric of a self-defense war.
I’m pretty sure that’s the whole Cambridge Analytica - Trump thing anyway.