I agree with this post relatively strongly. As someone relatively new to the EA scene, I found the jargon and language quite off-putting and would result in annoyance/feeling like an idiot plus some Googling later on. I'm unsure why we can't just say "What would have happened otherwise" rather than "Counterfactual". I personally try and play down this language as much as possible, especially around people newer to EA because I know the effect it had on me.
I think this post plays into a stronger point that certain aspects of the EA community actually are unwelcoming. Or rather it feels a bit like a secret club with a high bar to entry at times and there is almost certainly an intellectual elitism feel to EA occasionally (see in-group + tribalism). I think that descending further and further into niche phrases, elitism and not keeping the message as open to as many people as is not the right way to go.
I'm strongly in favour of making EA as widespread and as broad as possible. Sure it might dilute job applications or have a few other unthought of negative side effects. But imagine having thousands of more people earning to give for example or contributing their ideas and insight into EA. I wonder how many people have turned away from EA because of Elitism, Jargon or feeling unwelcome? that doesn't feel very EA to me!
Footnote: I realise this comment might come off as a bit bitter. Contrary to that, I really love the EA community and think it has enhanced my life so much in so many ways, this is just one aspect that I think could be improved somewhat - The onboarding of new and potential EAs!