"From boils, mildew and dirt / I've brought forth new beauty and new worth." [1]
Let's call them crippled interrupts. As long as you don't think of them as a message queue...
In their defense, the original signals were there mostly for "handle this or I'll terminate you" conditions. Then stuff got bolted on...
[1] Possibly LLM hallucinated translation from a Romanian poet. Although it did give me a link to a paywalled essay that I couldn't verify.