Tweet size is limited to 140 characters only. This prevents one in conveying a complete message when it is necessary to use more words to pass on your thoughts with context.
Visual content except pictures can not be uploaded on Twitter. A tweet can only comprise a plain text, a single picture and website links.
Your Tweet Disappears Very Fast
If your tweet is not read by your followers soon after you posted it, it will disappear under thousands of new tweets, and will not be quickly visible to read, unless specifically searched through.
It Can Become Boring
Unlike Facebook, Twitter has not much to offer like pics, videos, games, music, personal profiles and business pages, etc. Twitter can become boring if you do not see interesting tweets on the screen for some time.
Time Consumption and Addiction
Twitter can become addition for some people. They will keep on checking new tweets, relevant or irrelevant, expecting to find something new and spicy.
It consumes their precious time and also keep them constantly engaged with Twitter either they are at home, office or driving the car home or office. This proves to be unproductive and waste of time.
Also read about Advantages of Twitter