I wonder if its a bit like the "uncanny valley" effect. Aliens are, well, alien. You don't expect them to look human (except of course that so many do but they look exactly human). However a human face that is distorted and just looks off, all the time - maybe that could be difficult to get used to.
Two examples I can think of: Hex with his burned face I am sure I would find really hard to get used to in real life. The other is from the movie "The Elephant Man". As shown in these examples friends and frequent acquaintances can get used to it because they see the person inside and that is what they first think of, but anyone who only occasionally encounters them would struggle I imagine.
I am pretty sure from my own limited experience that I would find it difficult not to react negatively to someone I didn't see all the time, while being occasionally surprised by the face of a close friend when its difference breaks through my friendship filter. I would smile and talk to them but I doubt I could hide all my automatic reaction. Even a slightly wonky eye can be off-putting at first. Not something I would be proud of but still something I would have to work at.
Especially in the Nolans case if they are encountering new people all the time on missions, not having to deal with an automatic emotional rejection would be helpful I think. Maybe if Andrew had been around longer he might have developed some close friends such as Val and Jeckie with whom he was able to relax and take off the mask in their private quarters.
The red eyes are a bit problematic for me since Ferro Lad was always shown to have normal humanoid eyes through the mask slits.
The red eyes are likely to be because Douglas is scanning the multiverse to find a timeline he can find peace in.
Good thinking Thoth.