Thank you for this! I've said the same thing and had to deal with salty downvoters earlier today. Companies pay WITCH companies billions of dollars for their services yet a lot of pretentious hackers just don't see the value.
For an executive, it's easier to justify outsourcing to a large consulting firm simply because of the security afforded by the choice and the ease of justification; rather than any technical abilities they may or may not possess, and certainly it does not imply its correctness.
The anecdotes you hear are from a engineering perspective, which is where the consulting firm has to walk the walk, exposing their true abilities. It is incorrect to dismiss that as being "salty" or "pretentious", and tint them with an angle of "discrimination". The lack of processes and guardrails in these consulting companies is an objective fact.
People understand the world through dimensionality reduction and lossy compression of information in domains that they are not involved on a daily basis. This causes an inherent issue when you stack these phenomena across multiple organizational levels; this is how you end up with Intel's or Ballmer-era Microsoft's management failures, to use some non-WITCH examples, or the issues that we're talking about in this article.