I have been told that when laying out a PCB to keep all the polygon pours uniform on each layer. So, for example, in a corner of the PCB, you do not want the pour on one layer slightly offset relative to the other, like this:
The red layer is the top layer, brown is the second, blue is the third.
I have been told this is bad, but why? No one can give me a reasonable answer, and I don't want to do something just because someone told me to do it this way, I would like to understand what issues can come up with this sort of design.
Or is it just down to aesthetics?