* Hair Growth Cycle: Hair grows in cycles (anagen, catagen, telogen). Plucking only removes the hair shaft, not the hair follicle itself. The follicle will continue to produce hair according to its pre-determined characteristics.
* Thickness and Texture: The perceived change in thickness after hair removal is often due to the hair being cut off at the thickest part near the skin. When it grows back, it has a blunt end, making it feel coarser. Plucking also can give a similar effect. The hair follicle does not change though.
* Darkness: Hair may appear darker after shaving or plucking because it hasn't been exposed to sunlight or other factors that can cause it to lighten.
* Possible side effect: If you pluck consistently for a long time you can damage the hair follicles. This may result in slower, thinner hair growth, or even permanent hair loss in that area.
* Ingrown hairs: Plucking can also cause ingrown hairs.
In summary, plucking your mustache won't make it grow back worse in terms of the hair follicle itself, but it can cause temporary textural differences and potentially cause ingrown hairs. Repeatedly plucking can damage the hair follicle in the long run.