While I'm sure that a lot of said people are complaining only due to mental problems, there is a certain subset of the population that is abnormally sensitive to light of one or another color temperature. While most people perceive a 5000-6500K light as "brighter" due to how the human eye picks up different color temperatures, some people perceive a 6500K light as blindingly brighter than a 3000K light even if the 6500K light is actually producing less light as measured by a photometer. A couple months ago, I ran a test with a friend of mine (and former FG member) who was complaining about the new stock LED lights on cars as being misaimed - I don't have any problems with them on the road or in oncoming traffic, so I had him come over to check out the LED conversion on my 4R; he found them blinding compared to the stock halogen light sources even though the beam pattern is the same and he was viewing the lights from above the cutoff. We later compared a couple of Mustangs with stock lighting, one with HIDs and another one with LEDs, viewing the headlights from well above their cutoff lines. Turns out they aren't misaimed, it's just his photosensitivity in that particular spectrum. Not sure night driving glasses would help.
Night driving glasses might not help with HUDs - a lot of them tend to be in the same amber spectrum as those glasses are.
That said, there are some other objective issues with car HUDs. Depending on design, they can be difficult to read if you have astigmatism, even with glasses. Another issue is automatic light level control sometimes not doing a good job along with auto contrast. They all still have issues with washing out in bright lights, too.