I love the rain. Oddly enough I usually get very good times on my 11 mile commute when raining. I think it is fun!! OP said it very well. Otherwise, REI's brand says it right. 'Never a bad time to ride.' I love the looks when I told someone that I rode in the rain. Just funny.
I don't own "rain gear". I put on a nylon jacket and long cycling pants. I have booties for my shoes too. Everything is just insulation from the cold. The only problem is fogging glasses when I stop.
I will avoid freezing temps. Freezing rain just sucks.