I've been looking into the background of Valentine's Day, it appears it wasn't constructed by Clintons and Hallmark but based on a series of misapprehensions on how many martyrs there were called Valentine, when their Saint's day (or days) was (or were), what (if anything) they have to do with romanitc love, what date Chaucer was talking about when he writes about 'seynt Volantynys' day, and a convenient mash-up of the results of this with a Roman fertility festival. But people have been sending Valentines since the 15th century. I'm not going to check but I'm going to hazard a guess that Clintons hasn't been around that long.
And as for the argument that you don't need one day a year to tell you to make a loved one feel special because you should do it every day; well, I'm willing to bet that you don't. I've heard more than once that over-use of the phrase 'I love you' devalues it, but I think that's categorically untrue. Using it when you don't mean it devalues it, using it and then behaving in an unloving way devalues it, but I don't think you can ever say it enough. If you can't remember when you last told the person you love that you love them, you need to say it again.
I am lucky, I know, to have someone to celebrate with and someone worth celebrating. But one of my most memorable Valentine's experiences was a year when I was single and seven friends and I did a 'secret valentine' with a budget of £3 each, pulling a name out of a hat. I got a red fluffy heart that vibrated when you pulled a string (if memory serves me correctly it was from Ash), John won by giving Ceri a bin bag full of inflated balloons and a pin, which when she popped them each had a letter inside spelling out a message. Then we all went to the cinema to indulge Julia's crush on John Simm in 'Wonderland'. That year I also sent someone an anonymous home-made valentine's card and a kinder egg. It was an unrequited crush but it felt good to send it, and I'd like to think that it made him feel a little bit special that someone had gone to all that effort for him.