The problem, as I see it, is that the Flash editing environment doesn't have a widely-accepted descendant, and the person you're responding to is right - there's not really a contemporary editor that is as easy - and more importantly: as potentially deep (as it was also shallow) - for non-techies to pick up and work with.
There are plenty of options today for technically-minded or 'computer people' to work with, but there's a dearth of options for the 'merely' creative to play around with and investigate.
A lot of the magic from the 'old' (mid?) web came from people who had very little initial interest in the technical nature of the solution from just going ahead and making Cool Shit™ anyway. Some of those people might then relish getting their hands grubbier and delving deeper into the technical guts (eg. Praystation et al).
- ed : for the record, at the time i was also critical of the proprietary nature of Flash.
I was a "flash developer" for some time around 2005, but the Flash environment (what was it called, Macromedia Flash?) never really "clicked" for me. I was able to put together some interactive visualizations and even little games, but it was not simple for me. That changed when Adobe Flex and ActionScript came along. That's where I felt right at home. But I'm fully aware Flash made much more sense for others than it did for me.