This is an incorrect understanding of history. Eliezer Yudkowsky more or less created the rationalist movement, out of which EA emerged, as a way of funding AI safety research. MIRI is older than EA.
My understanding is that EA mostly came from Peter Singer's ethics. The "rationalist" movement adopted a lot of the language and metaethical principles espoused by Singer, but Singer has not (to my knowledge) indicated particular interest in AI. The books I've read by him mostly focus on animal welfare and human welfare in developing nations (cf. "doing the most good").
Peter Singer happened to write primary source material, but your comment is like saying the EAs came from Jeremy Bentham. EA the organization began with LessWrong which, again, was all along a play to generate funding for AI safety research.
Edit: The original version of the comment implies LessWrong is the single precursor to EA, which is wrong. But it is a relevant and influential one.
The key distinction between Bentham and Singer is that Bentham is dead (unless you count the auto-icon!), and Singer is actively publishing books about EA.
I have no doubt whatsoever that EA the organization, LessWrong, and MIRI are all instrumental in EA the movement. But my understanding, including from actually reading just about everything Singer's ever written, is that the applied ethical groundwork for EA was laid at least a decade before LessWrong or MIRI arrived on the scene.
I was reacting to your original post which implied that speculative concerns have marred EA the movement by pointing out that EA the movement has had close ties to speculative concerns since the beginning. It's a large, complex group with many on-going projects. LessWrong's top charities are still meat and potatoes human development in the 3rd world.