It's intended to be an amusingly simplistic strawman in order to contrast with and highlight the actual (deeply) complex reality described thoroughly through the rest of the article.
They don't actually think anyone who suggests IRB approval is very mean and very bad, that line really isn't the thesis statement. If you read a bit further I think you'd be less annoyed by it.
Assuming the author isn't being disingenuous, what does this line actually bring to the table? If the article is thoughtful and nuanced, why not write with the maturity that a thoughtful and nuanced topic deserves? You can do it in a way that invites thought and deliberation and isn't stuffy or overly serious. I just don't see what value interjecting this kind of preciousness is supposed to bring. If it's supposed to be funny... I mean... it isn't.
If you're really asking what the point of humor is, I don't think there's any answer you'll find satisfying. I'll take a stab at it though.
In this case, it functions as a hook; it's there to give you a slight chuckle before diving into a long and relatively dry informative article. It's some clear sarcasm makes you evaluate the supposed assertion made - that people who push for IRB evaluations are meanie-heads - and challenges any preconceived notions you might have of it being a simple "this is good" or "this is bad" thing either way because of course it's not that simple. This invites the question to the reader: if it's not as simple as that, then how is it actually?
Of course, if the tone doesn't land and you read it as a factual statement - and, importantly, it's so distasteful that you immediately bail and don't read the rest of the article to see what it's actually about, and just assume it's a petulant tirade against IRBs - none of that works. If you're at all interested, I would recommend reading some Adam Mastroianni / Experimental History posts, as it has a very similar feel but plays to the strengths of the tone a bit better (IMO). This one [0] actually touches on the use of humor in scientific papers, and I think makes a pretty good case for why clinical language isn't necessarily a good thing.
It seems you'd answer your own questions here and maybe some of your frustration if you actually proceeded to read the rest of the article, which explains quite clearly the point being made. You being exasperated by the tone or style isn't really relevant to the substance of what was written about, or to anyone else really.
They don't actually think anyone who suggests IRB approval is very mean and very bad, that line really isn't the thesis statement. If you read a bit further I think you'd be less annoyed by it.