I just feel like we should look at this a bit more critically though instead of just blindly accepting it because it lines up with our own beliefs and biases.
Of course, no one should blindly accept any idea. I don't think just sharing the article is suggesting we do that though (though I recognize you mention other discussions, and maybe there was some over-eager acceptance going on there).
I think the article is very clear that they're simply presenting the idea and asking for more investigation into it. They refer to it as "a new direction for mental health research" while acknowledging its potential limitations and the importance of current treatments like pharmacotherapy, being clear that they're not suggesting that be removed.
"As for mental illness, to be clear, we are not suggesting that psychopathology should be left untreated... We acknowledge that the pain–brain theory about the link between suicide and psychopathology does not explain all mental illness. However, we think that it is worth further consideration, as it asks novel questions, suggests testable avenues for research and has profound implications for clinical practice and risk assessments".
So the article itself isn't asking for blind acceptance; quite the opposite, it's asking for more research into the subject and just setting out the basics of why that may be worth it.
This article was written by two people, Annie Swanepoel and C.A. Soper, and seeing as the person listed first is usually the "lead" or the person that contributed the most, I don't think it makes sense to attribute this work to only Soper.