I can't seem to figure out how to search for the number of photos uploaded to flickr are of ISO 100-400 vs number of photos of over ISO 400.
Regardless, just because the majority of my photos may be shot in the lower ISO's, I still count on my camera to do well the rest of the time as well. It was one of the major reasons why I and many others move to FF in the first place, for better low-light capabilities.
Just going by my flickr account, you could say the majority of my shots are in the low ISO's. However, what you don't see on my flicker are the close to 100k shots I have taken using high ISO's. I don't post to my flickr the thousands of shots I take at my friends weddings, birthdays, events, retreats, family, everyday life, etc. Flickr isn't really the place for me to share those images.
Just click on a hundred random shots (say, the first 100 that come up) and look at the EXIF.