I also built a lot of stuff in Flash/AS back in the day, and even rode the wave into AIR for a while.
The OOP system, event handling with spaghetti code, and high level graphics abstractions just never bothered me. Things worked, and the nature of the beast is I didn't have to worry about maintainability so much.
Nowadays it would be different. I don't think Flash or Actionscript would be quite as fun. For out of the box engines, Unity->WebGL is far more powerful imho.
PIXI.js and any compatible spritesheet animation package gets you more than halfway there, using the same OOP scene graph paradigm, for people who really miss the Flash approach. Not the same level of IDE integration, but, still..
At least least I looked at it, which was years ago, and successfully ported over some old flash apps.
I was maybe 13 when I first used Flash (v3 in about 1999), way before I had much experience with "proper" coding. The fact that I could use it, the same tool professionals were using was what made it so special.
I'm sure it's coming.