HTML5 not as good as native for Mobile

Mark Zuckerberg has released statements stating that they had to rebuild their app in native for iOS and now they are redeveloping their android app to be native due to the massive overheads HTML5 was causing in their app. There are also reports that apple are restricting some javascript speed/functionality due to 'security concerns' which sounds quite bogus. This is a move to keep native apps as the priority method of delivering both products to customers and profits to apple.