Tina and Bubble.io have no overlap in terms of intended market. And Tina isn't even remotely 'Wordpress-style'. The idea is that you -- a developer -- already have a beautifully coded, optimized website/webapp. All you want to do is provide an interface so non-devs can edit content, and that's what Tina provides. It's an open source toolkit for providing an editing UI. It's not a CMS or 'walled garden' tool that you build your site/app inside, nor is it yet another wordpress clone.