All kinds of graphs are misleading if we expect them to be visually perfect. If you look at http://www.nasdaq.com/symbol/fb for example, their graph goes from about 30 to about 31, so if you read it the same way you might think Facebook stock has been almost to 0 a bunch....

The question IMO is not whether it is visually misleading but whether it conveys information in a usable form, and whether the information it conveys in that form is misleading, and I don't see it.

If we adopt a visually perfect line doesn't that mean all graphs must be linear (no plotting on non-linear scales, even though this is useful in some contexts), start with an origin of (0,0) and so forth? What percentage of graphs do you see that obey these rules?