Let me begin this brief reflection by identifying as an Evangelical Christian who affirms that the greatest love in history was God sending his own son so we might believe in him (John 3:16) and that God's love is demonstrated in Jesus dying for us (Romans 5:8).
Let me also agree that human hearts produce idols, i.e. objects of worship other than God. These idols can be materialism and occasions like Valentine's Day do pander to that with its flowers, chocolates, greeting cards, etc. Let me further agree that relationships, romantic love, acceptance by others and sex can all be idols.
But let me also say I am fed up with Christians who can only point this out on Valentine's Day, who forget the saint who married Christian couples or who want to point this out simply to dismiss the day, who so focus on human sin that they forget the original goodness of humanity and how we all bear the image of God. I am fed up with Christians who so focus on how we can pervert love, that they forget that our ability for love comes from God, that our altruism goes well beyond the demands of evolution because of God's image in us, which means our ability to love.
Why is it so many miserable souls can only ever be about what they are against rather than what they are for and only ever see the other as embodying what they are against? Do they wonder people prefer atheism or anything else to a gospel of negativity. Be what you are for, the love of God and the transformed love of others rather than spending all of your time pointing the finger. Yes such a critique is valuable; it's also predictable, negative, unattractive and not always as Prov 25:11 says 'Like apples of gold in settings of silver Is a word spoken in right circumstances.'
Bought both my darling wife and dear son Valentine's Day presents, and proud of it!