Why does fluorescent lighting make you look bad?

The drawback with fluorescent light is that it makes the skin imperfection look very clear. If the light is intense, then it can make you look older and less appealing. This is one reason why people avoid fluorescent light and standing near it.

Fluorescent light has less colour rendering index (CRI); this is the ability of light to render the right colour of the objects. This light would make you look tired, less healthy, and even pale. Next time notice this when you see someone standing in fluorescent lighting. 

If you stand in the white light, it will make you appear pale and less healthy as it takes away the pink complexion from your skin.

If the fluorescent light is right on your face, then your eye bags would become even more prominent. If it is strong and directly on your face, then you might appear older and less healthy.

In the fluorescent light, the face lines become more embossed. Particularly your smile lines and crow feet would become more extrusive. Because of this, your skin might appear dull, and you would look less attractive.  (See why do I look different in different lighting?)

These lights do not brighten the objects well as compared to the yellow light. Therefore, it would leave more shadow details.

This is another disadvantage of fluorescent lighting that changes the colour of the objects. As you apply the makeup under yellow lights, its look would be quite different when you stand in fluorescent light. You might not look that attractive, and your makeup would also appear a little offbeat. (See, why do I look ugly in some mirrors?)

Another issue with the fluorescent lighting is that your acne would become more noticeable. People who have acne would always want to avoid fluorescent light as it makes it more visible, making them look bad.