I am fair skinned and have fine hair which makes my eyebrows and eyelashes looks sparse. Without make-up I feel like my features are undefined and I look void of color. I don't wear make-up all the time, I work in a small casual place where I certainly don't have to impress anybody and don't feel I have to take an extra 10 minutes and put it on to go work, the supermarket, or the gym. When I go out anywhere that is not supercasual, I usually wear make-up. Make-up makes me look polished, so I personally think I would not look right if I was dressed up and wearing no make-up. Same thing with job hunting, I felt make-up helped me look more professional. I prefer neutral colors that emphasize my features and usually will wear foundation, eyeshadow and liner, mascara, blush, and either a lip gloss or lipstick. I also will out my eyebrows with some brown shadow which makes a lot of difference.
In college I used to wear it all the time because I feel better wearing it. One day I chose not to for an early class and I had several people ask me if I was ill
However, I feel make-up is for the person wearing the make-up and not everybody else so it is crazy to say it is rude not to wear make-up. This goes for anybody, even if they are pale, have scars, blemishes, ect., they are not obligated to wear make-up. If it doesn't bother the OP's boyfriend, I fail to see how it should bother her mother. If the OP's mother considered not wearing make-up rude, would she consider the following decisions about somebody's personal appearance rude to their SO: wearing a tee and jeans or other casual attire, being overweight, not fixing teeth that are a little crooked, or dying hair to cover up gray, ect. be considered rude?? I feel the extent of etiquette of personal appearance having good hygiene.