Something could sort of be made to work, but DIVs are not enough to support all of Spine's features. For example, there is no way to render meshes or perform clipping using DOM elements. A renderer that supports only region attachments would be possible. Note that Spine's bone transforms can result in rectangular region attachments becoming rhomboids. That is possible with CSS skew, but it would be tricky to get everything to behave exactly right because Spine's transforms are computing vertex locations (even for region attachments) while DIVs would need to be placed to match. Doing that can be tricky for skew, scale, and negative scale. Lastly, DOM manipulation has a lot of overhead and rendering is not optimized like it is for games. A skeleton is generally being animated, which means all the DOM elements need to be modified 30 to 60 times per second. Unfortunately that is unlikely to perform well.
