Conservatism has three centers of gravity:
1. The wisdom of centuries and even millennia, adapted to the present day. (Implied teleology)
2. What Grandpa and Grandma used to do.
3. What I think the adult world was like when I was a child.
Liberalism has three centers of gravity:
1. Where I think the culture is gradually headed. (Implied teleology)
2. What seems Nice, and therefore somehow moral.
3. What's hot right now.
Yes, let us make allowances that most ideas, and certainly most people, do not adhere entirely to one or the other or the other. Still, there's something to it.
Considering it this way, it's easy to see where sneers develop.