I seriously can't remember any (incredibly) widespread use of Silverlight – could you elaborate? The only instance I noticed it was with a video streaming platform.
I don't think Silverlight had a mass amount of public use (Flash and Applets were still available at the time - so there was no pressing need).
But MS really did earn a lot of bad will from their dev community who had been pushed to learn yet another framework which ended up dead.
I rarely even use my PC anymore. I basically then it on once a month to download the gigs of updates. It's interesting that Silverlight still listed at the top of optional updates.
There must be a few businesses and schools who bought into the hype and built their internal app on SL.
My previous employer sells a legal review & production solution with a Silverlight UI. I left half a year ago, but if all is well they have just finished reimplementing it in Angular.