I do not think Edge Animate collapsed because of demand issues - though I don't really know - I'm not privy to the internal Adobe numbers and business strategy discussions.
However, there were several circumstantial events that occurred which would guarantee a "fail" rather than just weak demand. Until these events occurred Edge Animate had a growing number of people joining the Edge Animate Forum (I was on the Forum for over a year and a half at this time) and an ecosystem of satellite web sites devoted to Edge Animate instruction, tools & demos - much like HypeDocks is for Hype.
1) Adobe pulled the plug on the entire Edge ecosystem, Edge Animate was the last to survive as a stand alone. Unlike some of the other Edge software, the feature set & technology never found a home. Animate CC as we all know has no Edge Animate DNA in it, except to co-opt the name.
2) Summer of 2014 - Most of the US dev team was pulled from the project and replaced with a team from India. Sarah Hunt the project manager left a short while later. Losing Sarah was a blow. Like @jonathan & @Daniel on this Forum she was an active participant and offered guidance and insight that only someone on the development team can have.
3) October 2014 - Absolute Disaster of a release. This was the "jQuery-free" update. It was hard to believe Adobe would allow such a bug ridden, poorly tested product to be offered. Then Adobe really didn't do anything to correct it in a timely manner (months passed with anemic fixes). Users jumped ship. Most Forum "regulars" evaporated.
4) January 2015 - Adobe effectively announces the end of Edge Animate (stopping active development). This was way sooner than the official announcement in December 2015. But the trend in January 2015 was obvious. The Edge Animate Forum reacted like a member of the family died - first shock, then genuine grieving. People were consoling each other. Adobe management was silent: no definitive prognosis about Edge Animate, no apologies or explanations... nothing.
If Adobe wanted to deliberately torpedo a software product they couldn't have done a better job than the steps outlined above. There was no excuse for their unprofessional, irresponsible behavior. It wasn't that they terminated the program it was the manner in which they did it - leaving their user base hanging with a defective product. It was a complete disgrace.