Interesting! How about this:
Plot[x^2 == 2 x, {x, -3, 3}]
It would seem that Plot[a == b,...]
is evaluated as if it were Plot[Subtract[a, b],...]
. This way you can visualize the solutions of a==b
as the intersections of the plot with the x
-axis. This is the only justification that comes to mind.