Stupid graph or stupid me?

Question

Reading the Microsoft TechNet article "Test results: Extra-large scenario (FAST Search Server 2010 for SharePoint)", I came across this graph.

Now, am I stupid (and if so, could someone please enlighten me), or is this graph just stupid? To me, it seems like it's created with MS Paint instead of reflecting real values - I can not make sense of the graph as it seems like any given value on the horizontal axis (Queries per second) can result in multiple values on the vertical axis (Latency).

EDIT: Thanks to all who contributed, the curves (not graphs) make more sense to me now. My conclusion to the original question is somewhere in the middle. I admit some stupidity on my own behalf, but still think the graphical representation of the data is quite stupid, as it fails to clearly communicate what it should.

Answer 1

The only mathematics here is whether these curves represent functions, which they do not. They represent data taken as a function of time. these curves just show the behavior of the system with increasing time.

Answer 2

Reading the article you mentioned, it seems to me that they did multiple runs of the same question, which is why you get multiple values for a given number of queries per second. What seems very unorthodox is that they polished that by drawing the lines which seems to reflect the timing of the measures (you get sort of a dynamic trajectory of the system).