> there is such a thing as software engineering
Which differs from place to place, yes. Not every program has been accredited but still provide software engineering degrees, perhaps with elements that would not be found in another's curriculum.
> and the people most strongly insisting to use the title don't practice it
Just because you don't have an accreditation does not mean you "don't practice it".
> Like I said, you can legally use it, but licensed engineers are rolling their eyes when your back is turned.
Good for them. They can roll their eyes all they want, it doesn't make them more right to do it.