It would be impossible to do any work at all without making assumptions.
This attitude belies the fact that of the 1000s of assumptions you make every day 1 or 2 will end up being incorrect, but it's usually very, very hard or even impossible to know which in advance.
Yes the point would better rather be made as "continually question your assumptions" especially when troubleshooting (hence the value of having a rubber duck).
The original point is invalid, although one could say that being good at systematically validating and invalidating assumptions is the sign of a good engineer.
One who doesnt make assumptions at all just wouldnt do anything, though.
I assume that when I press a key on my keyboard, the corresponding character will show up in my code editor. If I couldn't assume that, I doubt I'd see the use of pressing any keys at all.
(For clarity's sake: Not disagreeing at all, just illustrating your point with a reductio ad absurdum example.)
It’s fine when you don’t do it deliberately. It’s just that about 100% of the time someone says “I just assumed…” that is the source of whatever problem you are having.