Some flies are tied backward on the hooks just for this purpose. They have never gained popularity.
Does it matter? Maybe but probably not in most situations. I think mayflies definitely orient themselves into the wind. I've been in situations when the a wind blowing downstream caused the mayflies to orient themselves upstream to face into the downstream wind direction.
I've seen mayflies spin when the water they are on is a vortex. So I believe the direction and way a mayfly faces is a combination of perceived wind direction and changes in water surface flow patterns.
I don't think caddisflies orient themselves in any consistent way whether hatching or egg laying. If they do, I'd like to see the reference to this fact.
A trout's central vision is much worse than a humans. We have 14 times the density of cones and rods in our central vison (macula of the retina) than a trout. That is greater than the difference of an eagle's vision vs a human's. So trout see detail very poorly compared to us and they need to get very close and need time to see detail.
I believe most fly fishing situations do not give a trout the opportunity to examine a fly in great detail before it must decide to eat or not eat. If a trout had to look at every piece of possible food that carefully, it would starve because it would waste energy.
A helpful way to think about trout's decision process is the concept of triggers. Triggers are specific apperances or behaviors that the trout look for to decide whether to eat or not eat.
Triggers can be positive or negative. Drag is the big negative trigger. Proper size, shape, color and behavior are positive triggers. Is the direction a fly faces a behavior trigger? I don't think so. I don't think most trout use the direction a fly faces as a positive or negative trigger.
I think of it this way. If a fly facing in the wrong direction caused significant refusals, backwards patterns would be more popular and there would be article about that fact. I just don't think it is important.