I think Silverlight was making deep inroads in the enterprise market for rich internet apps and that this was a growing customer retention issue for Adobe with Flash. That's part of why they invested so much in Flex and AIR as a more engineering-centric alternative to the Flash app's designer-centric timeline interface. They wanted to shore up what they were losing to Microsoft.

The consumer usage of Flash was most visible (games, cartoons, brochure sites, video streaming) and Apple's evisceration of that market was what ultimately killed Flash, but things were already looking grim on several fronts before that happened.

Lots of enterprise apps like ERP and that type of shit may STILL require Silverlight for older versions. It was huge in that market.

Edit: I replied to the wrong comment, although this still stands!

I still miss macromedia Director though. I learned to program with HyperCard and then director, and I always thought it was a shame it got canned when adobe bought it.. it was much nicer in lots of ways, although the player was more heavyweight. Actually, I don’t think I’ve ever really found a proper replacement for HyperCard!

Perhaps you would enjoy Decker: http://beyondloom.com/decker/

Yeah, coming from back at that time, to consider Silverlight at all is to give it too much credit.

Jobs and his unwillingness to support it on iPhone killed Flash, and that's that.

Internally Adobe hated Flash. It strode right past Live Motion which used the UI paradigm of After Effects to produce animations which didn't cater to the traditional key framing model Flash was built on. I feel pretty strongly that there were forces inside Adobe that wanted to take advantage of the merger to bury the Macromedia IPs. Adobe had a great relationship with Apple. Photoshop was finely tuned to work on Macs and the majority of the creatives using it were working on Macs. Adobe could have threatened to put Apple's computers in the ground by limiting Photoshop support for OSX in 2009 in order to gain support for Flash on iOS. They didn't. They just never thought of Flash as an Adobe product. If Apple stopped supporting Photoshop things would have gone nuclear.

That would definitely explain why they were so half-assed in their attempts to adapt to HTML5.

Word on the street, at the time, was that Apple and Adobe collaborated actively on making Flash work on the iPhone without straining its battery. It is the failure to achieve that goal that prompted the whole about-face.

The only time I ever interacted with it knowingly was the LEGO MINDSTORMS EV3 software.

The original Netflix streaming site used Silverlight, I'm guessing because browser DRM wasn't up to snuff at the time. That's about the only time I willingly used it.