I read a little way into the article to see whether he'd explain the lack of axis labels or just how the graph maps to anything real. Nope.
The article is reasonable but the loops just annoyed me too much.
I had the same thought at the first glance at the loopy graph, but decided to take off my nerd hat and put on my "I'm listening to a business guy" hat. I think this is something we tech people tend to get hung up on too much... snickering at the slightly misused technical jargon and other similar errors (like this graph) that business people make and then not being able to hear what the person is actually saying.
Any non-technical, non-mathmatical person would look at that graph and say "yeah, you go around in circles for a while and then finally get things worked out" and I actually thought this was a pretty good post otherwise.
"He was saying a real startup trajectory might look something more like this" (emphasis mine)
When we're graphing trajectories, not functions, loops are certainly allowed (see e.g. phase diagrams[1]). Still, without labeled axis those graphs are pretty much meaningless, so I treat them more like an conceptual illustration.
Any non-technical, non-mathmatical person would look at that graph and say "yeah, you go around in circles for a while and then finally get things worked out" and I actually thought this was a pretty good post otherwise.