The weird thing is... going back to the thread... everyone was not talking about the lack of puddles or rain splashes, but rather due to the way the rain drops look.
Constantly posting the .gif (which does not even really look at the ground) and with stills like this:
Seems like some sort of collective "selbstäuschung" to me.
I think it's more that they didn't do anything to sell the illusion that those are supposed to be rain. They don't look enough like rain on their own, so that's why people complained. But even using the same particle effect, with enough audiovisual cues people will believe in the rain.