I recently tried to make sourdough with my starter, it didn't rise. Why is there still a crumb?
Looking at that picture you did definitely get a rise, in fact you got some big air holes. I would be happy to get that crumb, and I have baked plenty of bread. From the shape of it I suspect that what happened is that it simply spread out on you, rather than going up, which is common with dough that has a high hydration level like yours seems to be. 

Bread dough is a bit like water in that it will flow the path of least resistance, if you simply plop a dough down without restricting it or shaping it you'll get a spread. Shaping will help depending on the result you are looking for, but I would recommend you use a shaping basket, also known as a proofing basket when you do your final rise.