I do wish that people would stop using the term “progressive” to refer to the left. Do you think what they propose is progress? I don’t, so I don’t call them progressive.
It’s a historical term that accurately reflects their philosophy of man (i.e., the idea that there is no such thing as an immutable human nature, that instead man will continue to evolve into higher and nobler states, and hence society with that). ‘Progressive’ is actually therefore a much more accurate word for them than ‘liberal’ since philosophically they are very much the former and not at all the latter.