I consider few of the left's arguments progress - certainly not gay "marriage". It seems more regression into a dissolution of civilization to me. I refuse to use the word "progressive" to describe the left.
I agree entirely with you that few of the left's views are actually progress. However, unlike your decision, I choose to use their now preferred identification as progressives. The reason for this is they're shifting names because their views have discredited the title "liberal"...so I believe we should not allow them to slide away from their own negative connotations by now declaring themselves progressives and not liberals. If they wish to be called progressives then I will continue to apply the negative connotations to their new title because they have changed nothing but a name...the views are still the same. Eventually everyone will see progressive as failed a view as liberal and they will attempt to flee to another identification, but till that happens I wish to stick them with the consequences of their views.