“Creationism”, when used by itself, is almost always understood as denying the reality of bacterium-to-man evolution. John Harshman understands this.
Yes, one can put adjectives in front of creationism such as “Old Earth” and “Young Earth”, because they don’t modify the basic sense of anti-evolution. Everyone knows that YECs and OECs are anti-evolution, as evolution is commonly understood.
However, when one fiddles around with terms like “evolutionary creationism”, one invites confusion and misunderstanding, because the “ism” at the end of “creationism” is loaded with cultural resonances, even if the user of the compound term wishes those resonances didn’t exist and hopes to abolish them. Thus, the attempts by BioLogos etc. to talk about “evolutionary creationism” merely muddy the waters.
You fail to appreciate the weight of history in language – the loading of words with connotations that become widespread in a culture. The aroma of evolution denial clings to the word “creationism”, and that is why attempting to sanitize the term for use by evolutionists, by the addition of a qualifying adjective “evolutionary,” either fails or engenders confusion.
You might try attempting to revive the original sense of the word “gay” by using compounds such as “light-hearted gay” or “playful gay” in contrast with a compound such as “homosexual gay” – and see how far you get. The connotations of homosexuality that “gay” has picked up are, at least at the moment, impossible to erase. Words aren’t simply blank tokens on which we can write any value. They come loaded with history, culture, ideological slant, etc.