[GnomeChomsky]

Not to mention the massive elearning industry which has many, many years' worth of training content in Flash. Products like Captivate and Articulate can export to HTML5 these days, but converting existing content is a huge feat.

(FWIW here's where Adobe Captivate is with HTML5 support: https://helpx.adobe.com/captivate/using/publish-projects-htm...)