You are an example of someone who seems experience-free. I worked on DEWs for decades, with the objective of melting through aluminum fuselages. It does not require recondite theories of how metal is heated. The fact of the matter is that even shiny aluminum is not perfectly reflective, so you simply have to provide enough intensity on target that you manage to get about 4 watts/cm2 absorbed by the target. The rest is ineluctable. But aluminum is a lot more shiny when incided by microwaves, so the overall power requirement is higher.

As for fire, you have no appreciation of wild fires, which are notorious for freaks of combustion resulting from the fact that the "fire" is a 3-dimensional volume of space that is being twisted and convected by its own physics. This is not only "plausible," it is a fact of life. We have forest fires in the Pacific Northwest, and big ones at that, though we don't get on the national news all the time. Do you have any idea what it means when a forest has been soaking in hot summer days, exuding isoprene? It makes the very air semi-flammable. I took a drive into the mountains one summer day and stopped at a stream crossing to stretch my legs. Trees all around (conifers). When I stepped out of the car, it was like I had stuck my head in a bucket of turpentine. Absolutely no mystery why there are red flag fire warning days.

No, I don't think anything has changed. It is more a matter of the uneducated looking at something for the first time and being amazed.