If Twitter were on Shark Tank right now, Mark and Robert and MR Wonderful would be out due to lack of patent.
However, your point stands, twitter doesn't make much sense in the traditional business POV.
"The current state of patents and patent litigation in this country is shameful," said Cuban, owner of the Dallas Mavericks. "Silly patent lawsuits force prices to go up while competition and innovation suffer. That's bad for consumers and bad for business. It's time to fix our broken system, and EFF can help. So that's why part of my donation funds a new title for EFF Staff Attorney Julie Samuels: 'The Mark Cuban Chair to Eliminate Stupid Patents'."
https://www.eff.org/press/releases/eff-patent-project-gets-h...