Hi Lior Ehrlich,
Thanks for the comment!

I’m aware of the advantages of building graphs with SVG. In the case of the project I was involved, the data source included hundred of thousands of nodes and the same amount of edges. The user retrieves a subset of the data source and even the subset is enormous in size. Also, take into account that a force graph includes a simulation which changes the locations of the nodes. That means that you will have a lot of reflows if you are using SVG. We got poor performance with SVG using only D3 at first. All in all, the canvas solution was the preferable solution in this case.
I hope that my response elaborate the situation.