" One of the experimental features that I included was an "Export to Web" option. The goal of this feature was to make it easy to share games online without needing players to download an executable. As it turned out though, there was more initial interest in this feature than in the game engine as a whole. " <=== I believe that QBJS users like this feature very, very much and this feature is very successful. Sure!!!!!! This is the strong evidence: (the number of games is increasing. My guess: over 100 games after 3 years!)
https://itch.io/games/tag-qbjs
"Regarding point 5 of your post, I definitely think that if someone wants to create tools for games, the best way to know how to build those tools and to know what game devs need... is to make games!" <=== I totally agree with you!