If a professor presents these assumptions as "truths" (as they have done, quite literally, via this article), graduate students are strongly disincentivized from thinking about challenging or contradicting them - if they want to pass their course, if they ever might want to get a job in that department, etc.
What contemporary graduate macro everywhere teaches you is a set of tools. You then have to ask and answer your own questions. There isn't any "indoctrination" as you seem to be imagining. It's not different at all from doing a math PhD and taking a first-year analysis sequence, or a CS PhD and taking an algorithms class. It is exactly the same.
If you can take these tools and show that any of the truths presented in this article are false and can do it in a convincing way, then (as I have said elsewhere in this thread) you are going to be able to get a great job in whatever department you want.
Understand something about the incentives in science - surprising and counterintuitive results, convincingly demonstrated, can have enormous payoffs.
The way you seem to be imagining things work in economics departments and graduate programs bears little relationship to the way things actually are.
This is not the opposite of taking those as axiomatic truths.
You're also calling them truths and saying it's on me (as a novice) to show them false? This only proves my point that they are not properly examined.
Like I said, it bothers me.