The objective answer of why I think is BS is that an arrogant interlocutor, almost by definition, lacks empathyThis is an interesting formulation, and I think there is something to it. "Fake" experts are (all to often) merely people with "too much self-esteem" and too little comprehension of context. "Expertise" is too often a crutch for those looking to assert some sort of claim to social rank or status. Or, polish their "brand" for future 'business opportunities'.
The flipside of the analysis, however, is the juxtaposition of "objective" with "lacking empathy". Both are two ways to de-emotionalize a subject, and it is a good rule-of-thumb to ask if what you are seeing is one or the other. Also, to make sure you have enough resolution to distinquish the two variations. After all, it is quite common empirically for people to become emotionally attached to home-grown ideas,[0,1] and this is in fact quite common with startup founders [2].
What is juxtaposed here are insiders and the outsiders both of which are fighting for credibility and influence. And ultimately, the prize of "being right". There are times when having high-powered incentives and/or low-powered incentives either work or don't work in bringing to bear a new light on the subject.
Ultimately one needs to be a ~visionary (not run of the mill), or truly from left-field.
[0] "Not invented here syndrome"
[1] There is an emprical behavioural bias about "switching" opinions, even on trivially important positions, provided that the information on the position has bee made public to a peer group.
[2] Which, if unchecked, classically leads to the installation of a new CEO.