I don't think it's unreasonable for people to assume that = means equality, not assignment.
Edit:
In particular, the link posted in the second edit has a rather poor test using a and b, because it uses = in two different ways with no indication that the meaning of the symbol has changed. Maybe the problem with the test isn't just the people, it's the sloppy notation that assumes people with no programming background are able to infer when we mean equality and when we mean assignment.
Edit:
In particular, the link posted in the second edit has a rather poor test using a and b, because it uses = in two different ways with no indication that the meaning of the symbol has changed. Maybe the problem with the test isn't just the people, it's the sloppy notation that assumes people with no programming background are able to infer when we mean equality and when we mean assignment.