I'm of course no art historian of any sort, don't even play one online. However, yes, perspective, proportionality and light were being paid more attention to in art at that juncture in art. Often, in current and historical naive and current and historical primitive art, we see the same issues with bad perspectives and bad shadow treatment. That said, in many cases the artists knew but did not care and had a different focus. Still I agree that in many cases the artists didn't want this "interference". Just as today your roadside artists may not include all the municipal electric wires or all the trash or cloud shadows and so on in one of their paintings when capturing an atmosphere or panorama.