Evolutionarily speaking, one reason that people prefer the familiar over that which is unfamiliar is that

Familiarity is enjoyable.

Explanation:

It is easy to enjoy to enjoy a familiar thing because it tends to fall into popular stereotypes. Unfamiliar things require more effort to understand and they can be dangerous. It's a basic human instinct to stay in a safe zone.

unfamiliar things can be inherently dangerous

Explanation:

People over time prefer the familiar to the unfamiliar. To say the unfamiliar is potentially dangerous has to the with several factors in chief of which is comfort, perceived rewards, uncertainty and so much more. Some of the questions asked would be what happens when we leave our current state, would the next state be better of or worse than the current etc. All these leads to uncertainty and the fear of the unknown. As a result we tend to stuck with what we know rather than what we don't and if ain't broken why fix it?

the group received an extra pound of butter for christmas.

the annex was delighted to hear that we'll all be receiving an extra quarter pound of butter for christmas.