This really has more to do with hobbiest cycling culture than anything else. It in no way benefits performance. The inflammation alcohol causes is enough of a reason not to, especially in a sport where body weight is so important. I’ve read in the past that the effects that alcohol has on your recovery is significant enough that you’re better off not working out prior to a night out on the town. I will admit that I can’t find the that research now, so take it for what you will.