It's a fair question. But it's because the news reporting about it has been incorrect and has often suggested that it only applies to campaigns. That's why. I'm using reporters as a proxy for the public. And also, much of the public will learn about the feature from these reports.
As a political advertiser who jumps through huge hoops about what is and isn't allowed, what the definitions of different terms are, and how it's constantly changing and hard to keep up with even as a professional -- yeah, I can't expect others to have the time to keep up with it.
And even if they DO keep up with it, the standards are at times vague and enforced in weird, unexpected ways. What's a "sensitive" topic? Is talking about COVID masks a sensitive topic? I mean, it's recommended (now) by the CDC. But also, some people are anti-mask. There's a clear partisan divide on the mask issue. Is selling masks political? If a person wants to avoid Biden/Trump ads, should they now no longer see ads about a good deal on masks to stop spread of the coronavirus? (Companies that sell political t-shirts, even though they're not a political organization, have to be marked as politics. The content of the ad is important, not just the type of organization.)
But also, even if you're fully informed, there's little flexibility. You can't make an exception for an organization that you're a dues-paying member of so you can stay updated about how your money is being spent, for example.
Finally, that definition of social issues isn't the ONLY one (which, by the way, Facebook won't even describe to users who don't seek it out). Each individual issue area has its own definition. There are definitions about what is a "gun issue." On civil rights. On the environment. (Click "United States" at this link: https://www.facebook.com/business/help/313752069181919?id=28... ) This is super complicated and requires a large investment in time to fully understand.
I admittedly might be hyper-aware of these complications as somebody who has had to go through all this documentation to know what does and does not have to be marked as "politics" before I submit the ad for approval. (If you don't mark it properly, your ad can be delayed for days -- and politics is fast-moving.) Maybe Facebook users don't care. But there's no sense that I have from the way it was released that they sought user feedback, either from political orgs or even from the daily users of their website. What types of settings do they want? What kind of flexibility is needed? I don't see any evidence these issues were even grappled with. That's frustrating as an advertiser, that it seems like they just started with "how do we have fewer headaches?"