Glow is a term that usually applies to alcohol/oil fuel that in the United States usually includes nitro.
When electric motors came along, there wasn't much problem even when they became popular and common place.
But when people started building what was first called "quarter scale" they started using converted weed eater and chainsaw engines that ran on gasoline.

And using the term "gas" to describe any liquid fuel engine was no longer a good, clear way to communicate.

But people still refer to liquid fuel as gas.

And it's going to get worse, because the automobile industry is developing cars that run on alcohol based fuel. Oh man, is it going to be a mess when those things start running on glow fuel. They're already running on electricity.