Twitter relented and increased the limit to 280 characters recently. But many people still wanted a larger limit. Expressing ideas in 140 characters became an art. Tweets started out as 140 characters long.
Why can't send a tweet that's longer than 280 characters? I knew answers to a couple of whys from previous experience but I had to go look for source material to answer the deeper level of whys. I got into Adi's why mode today and asked the same question for the 280 character limit I keep running into for my tweets. Life is different with 10-year-olds around, they can keep asking why until you start saying 'I don't know'. 'Oh no, Adi is in why mode!', Groaned Pratham and our family mentally started preparing for the onslaught of the word why for the next 10-15 minutes.