I suppose what I'm trying to say is that in the case of positive opinions, it's not super common to leave them unprompted (see: all the popups in apps for "Like

I suppose what I'm trying to say is that in the case of positive opinions, it's not super common to leave them unprompted (see: all the popups in apps for "Like our app? Rate us on the app store!") whereas people angry at bad service have no compunctions about finding somewhere to vent, in public if they have to, and are super driven by their agitation.