I've frequently heard this theory, that Twitter's problem is that it's too complicated. I don't buy it. It has a simpler UI than Facebook or Snapchat, and it's not significantly more complicated than Instagram or Vine or Periscope or any other media sharing platform.
If you personally enjoy Twitter and derive value from it, it's easy to believe that people who don't get into Twitter just don't understand it it. My experience is that many people sign up, send their first tweet, and then say, "OK, I get it, and I have no use for this." I've helped my friends follow news sources and celebrities they like, but then they look at the wall of Tweets and say, "OK, I get it, but I don't want to read things in this format." It's not about ease-of-use for them, it's about the basic value proposition of tweeting and the Twitter feed.