If engineers are taught this, I imagine orgs like NASA, SpaceX, Boeing etc. must surely hire individuals who do not subscribe to this idea. Reliability IS important in these areas.
In my opinion, what this individual told you should belong to a business lecture, not engineering. If your systems fail in engineering, you aren't doing your job right.
Engineering something so that it is reliable JUST ENOUGH so you can make more money from it failing sooner is not a trade off between cost of producing it and its performance.
In my opinion, what this individual told you should belong to a business lecture, not engineering. If your systems fail in engineering, you aren't doing your job right.