1. For the lulz 2. For a disgruntled twitter admin who thinks they won't get caught 100k is a good haul. If you steal 1MM dollars and you have a 80k/year job you're in trouble. 100k in btc cashed out over a year or two - less of a problem. 3. I can't think of how you could make more, at least not without putting yourself at huge risk. 4. Maybe these tweets were just to serve as proof you did something else we don't know about yet, and you are getting paid for that. 5. Maybe you are a Russian operative, and your job wasn't to make money, but to try and find dirt in the DMs of Trump's political opponents.