I just read your blog and really like your images. Congratulations on your work. I'm going to follow your experiment. I'm trying a lot of different apps and sharing sites at the moment.
I think it's evolving that way because of the old adage to be honest...a picture's worth 1000 words. I have noticed the huge shift from people updating their statuses on Facebook with words a few years ago, to simply posting a picture instead. Instagram is a perfect example of the popularity and evolution of photography on social media. It's no mistake that it was one of the most downloaded apps (along with Snapseed) of the past couple of years.
People communicate visually and I think it's just easier to do so these days.