Why does First Win of the Day have a fixed cooldown?

First win of the day (FWOTD) currently has a CD of 22 hours. This is way better than a 24h CD because you can atleast afford to lose a few games without missing out on it the next day(s). However, I still find this fixed CD very frustrating. I feel really bad for losing when I have FWOTD available and it simply gets furstrating if it occurs multiple times in a row. I often just play Co-op vs AI in dominion to get this, but I find it very boring to do so and I feel like wasting time just for IP. It's not satisfying at all.

On top of that, I don't always play at the same time each day. Sometimes I'm only available during the evening while I can only play during the morning next day. Even though I have played each day, I would miss out on this bonus.

Other games that have daily rewards usually have a reset on a fixed moment of the day. Usually between 12 and 3 AM on the server's time. I find this approach much more satisfying. First of all, FWOTD would actually be "the first win that you get that day". On top of that, it's way more relaxing. You get 24 hours to win a game rather than having to get it ASAP because every minute you didn't get it, you'll have a minute less next day, which will keep repeating itself and eventually causes you to miss a day.

So Riot (Repertoir?), what is your reason for having this system for FWOTD? It feels unnecessarily frustrating for the players. There must be a reason, right?