Why must we 'prove" our love for someone to other people?

I mean honestly. Valentines day is such a joke. I just find it absurd that it's looked down upon NOT to get your "companion" something on a specific date that has no significance to the actual relationship. Does it really make someone shallow or terrible for not participating in this ritual of taking one day out of the year to be so generically typical? Perhaps it would be better to express unconditional love!