People pick progressive because they actually think the 'progress' in the word means progress. Just like liberalism, lefties have screwed up another word.
The root word for Progressive is progress and defined thusly:
1. a movement toward a goal or to a further or higher stage: the progress of a student toward a degree.
2. developmental activity in science, technology, etc., especially with reference to the commercial opportunities created thereby or to the promotion of the material well-being of the public through the goods, techniques, or facilities created.
3 advancement in general.
4. growth or development; continuous improvement: He shows progress in his muscular coordination.
5. the development of an individual or society in a direction considered more beneficial than and superior to the previous level.
Now the right can and will spin history and linguistics to fit their agenda, but to the informed it only makes them look dishonest.