Reasons For Endorsing HTML5 Game Development
Game Download Speed - It still amazes me that client side games exists and are still being developed. The download for these things is obnoxious if you do not have any of the game assets per-loaded even with broadband connects. They are also error prone given the constant updates that MS and Apple drop on your device. HTML5 goes a long way in eliminating this issue.
Objections For Developing HTML5 Games
HTML5 Versus Flash, Objective C(Apple) , And Java App(Google) Game Development Debate