Interesting. I didn't realize R' Steinsaltz commented on that. I haven't heard the Reform folks make that argument about fire. I've heard a lot of misunderstanding about "work", thinking it means "lots of effort", from various people. People without much education read the English word "work" and draw conclusions, but as you say, melacha is about creative work, hearkening back to the Creation that led to the first Shabbat. (And no, not "creative" in the sense of imagination or fiction.)