Valentine's Day VS St Patrick's day

How come people are so against Valentine's Day because it's "commercialized and is a made up holiday to sell candy" "why do you need a day to tell someone you love them" but when it comes to St. Patrick's day - NO ONE ever says its a made up holiday, or that it was created just to sell beer- or "why do I need a day to tell me when to drink" it's the same thing- you love people everyday but take a day to show even more love- some people drink regularly but take St Patrick's day to drink even more than usual.. What's the difference?