divisionbyzero
Valentines day has no emotional significance for me and DP either, we use it as an EXCUSE to spend money on each other because the rest of the time we don't have any to spare and I feel anxious about receiving gifts, this year even the day away was still too much. Birthdays and christmas are also 'excuses' - you'll also notice I said I hate going out on V-day precisely because it's full of couples who are there because they have to be.
I would've much preferred the original Roman orgy fertility festival in my slightly younger days, quite frankly.
My point is, it's obviously important to the OP - her H doesn't make an effort in general, and even knowing he was supposed to book somewhere on the ONE day it was 'his turn' he still didn't bother early enough, and as it's the same day every year, it's not like it crept up on him. The OP also said they USED to celebrate it, it's all fun and games if you're not V-day sorts of people, but if one person in the relationship suddenly decides to put zero effort in, I don't see how that's acceptable, no matter what your feelings are about the day in general.
Him doing this is a representation of how he acts the rest of the time in their relationship - ie not initiating time together, places to go, doing nice gestures etc., and the whole driving around looking for somewhere anyway - just, oh man.