They saw themselves as artists. And users benefited a great deal from that.
In fact, some aspects of the IDE were so good, that some 'developers' didn't even care to use it to develop programs. They produced cartoons instead. I think Craig McCracken's Fosters Home For Imaginary Friends was the most successful work of this kind.
In the place of that creativity now, we have cleaner code, to be sure, but we now also have an awfully boring technology war, and a load of unnecessarily complicated UI code.
I might miss Flash a whole lot less, if someone created a HTML5 authoring tool with the same toolkit the Flash IDE once had.
Arguably I think the saddest difference between Flash and Animate is the business model. In the old web, Flash was also partly so ubiquitous because it was sometimes so commonly pirated and passed around among aspiring developers/artists. In the Creative Cloud era it is a lot tougher to pirate, and can be a huge cost overhead for small or aspiring artists.
On top of that, it's also not easy to "watermark" HTML5 games. With SWF, you could create custom loaders and force ads and logos, both core revenue models for gaming websites.