Should we scoff the idea of love at first sight

Yes, while two people may cross paths and feel they are immediately "meant to be together" it is a shallow concept because the feeling of "first love" is based off of unrealistic ideas of each other.

Example: In "Romeo and Juliet", one of the most infamous stories about first love, they share sonnets, speaking as one - yet they disagree on their first encounter on whether if they should kiss or hold hands. Their connection is more likely considered infatuation (instense, but short-lived, adoration).

Love at first sight is an illusion - the wrong term for what is simply infatuation, or a way to sugarcoat lust.