That's a pretty error prone way of writing SVGs though. In well written code you would use a strongly typed API and that API would be exactly the same for a binary format.

Think about how you write Protobuf files for example.

In the circumstances where I actually cared I would use a strongly typed language with nice wrappers, of course ;) The reason why I love SVGs is you can just belt them out from scripts and it's the easiest thing in the world. Same reason why I love GraphViz and Netpbm.