It's not *deliberately* misleading in any way, it's just the wrong way to present the data. It's like missing capital letters from the start of your sentences or something.
In fact there are a wealth of things wrong with that graph
1) the tick marks on the x axis are between the labels, rather than on the labels (non-critical, but why?)
2) there are too major grid lines on the y axis (using just a few strong grid lines would make it easier to read)
3) it would be good to have symbols (e.g. crosses) at the data points themselves, as that's what the real data is
4) the resolution is crappy and there are horrible (JPEG?) artifacts; probably a copy-paste rasterizing issue
5) too many of the colours are too similar: lots of yellows and oranges (probably there are just too many lines, but dashes etc. could be added for disambiguation), although you can most disambiguate by order which is good
But they do at least have units on the axes, so that's a plus
Generally I would say that using lines to join points like this is a bad thing generally, but particularly when using non-linear axes like this it should be a crime. However, in this case due to the number of lines it does make it a lot easier to follow the values of individual flasks. It probably wouldn't have hurt to put the values at the right points on the axis though...
I suspect though its just that the journalists making this graph didn't know they should use the 'scatter' graph (with best fit lines, probably) rather than the 'line' graph (which is almost never the best choice)...