Best answer I ever heard for this was along the lines of "Maybe the lights we're seeing are in a wavelength THEY can;t see, they don;t even know how eye catching they are!" I don't buy it (they've abducted and tested enough people by now to know what wavelengths WE can see!) but it gets points for creative thinking, I guess...
So these hyper-intelligent beings (with technological capabilities unimaginably more advanced than ours) are deliberately (as it's are part of the design of the craft) expending energy on something they can't make use of? I think that's ascribing a certain level of dumbness to the beings, which isn't what I would classify as "creative thinking", it's more like projection.
Especially when the lights just so happen to meet aircraft regulations...
Well, so do we. A fair amount of gear gives off IR light—precisely because we can't see it. (e.g. security cameras, TV remotes)
Yes, but we actively try to reduce it. For example, the transition away from incandescent lightbulbs in the EU and much of the world over the last couple of decades.
