The day after my dd was born, my dh brought in a huge pot of daisies for me. He bought it because it was the biggest floral arrangement in the store he could afford. My mother almost fell over bec she knows I HATE daisies and here was this huge pot that dominated the tiny hospital room and I couldn't get away from it. Honestly, I'm not sure how after 15 years together, my dh didn't know that fact, but... I graciously accepted the gesture for what it was -- a big expression of love. (To this day, he doesn't know how I felt about that pot.)
However, if he had known I hated daisies and bought them anyway, given my hormones at the time, I might have gone whomp on his head.
So having BTDT, here are my thoughts:
1. Your wife's reaction was over the top. Is she always such a drama queen or is this a new development? If she does this regularly, how have you responded -- have you done so in a way that reinforces the behavior, have you called her on it, have you sugested couple's therapy, have you suggested she get her hormones/thyroid checked, have you just licked your wounds in private without confronting her? IOW, have you unconsciously helped create a codependent negative dynamic in which you cannot win and she gets to go on an emotional rollercoaster and enjoy feeling like a martyr? If this is a new development, what is going on in her life that makes her react this way? How can she get out of this negative situation and what can you do to help?
2. While I think your wife's overall reaction was over the top, I do find it her initial disappointment understandable.
I think the problem here is that you two have different love languages and/or different expectations. There are some people who would be happy with any gift -- even, say, a can of tuna or box of garbage bags, as long as it's a GIFT. Your wife is not one of those people, but you essentially gave her a box of garbage bags on Valentine's Day. You seem to think that investing time but ending up with a pro forma expression is enough. She does not -- She needs to be SHOWN that you love her by paying attention to details that matter to HER.
To you, red roses = Valentine's Day and love. This trumps the fact that your wife doesn't like them.
To her, red roses = symbol of the fact that you think so little of her that you deliberately got her flowers you KNOW she doesn't like. I have to admit that I simply don't understand why in the world you deliberately bought her flowers you KNOW she doesn't like or want when you could have just as easily bought her flowers you know she does like.
While I think your wife's expectations are unrealistic and frankly, demonstrate immature notions of coupledom, I also think you are not helping matters when you deliberately give her a gift you know she won't like (and allow her to ream you out for 30 minutes about it, forcing you to tell her to throw the gift away). It takes two to tango the dysfunctional dance, after all.
The long and the short of it is that I would strongly suggest you two get couple's therapy and find ways to get both sets of expectations more in tune with reality and to find ways to make each other happier.