Do you really think Twitter's and Square's boards responsible for companies worth $100B+ combined are not aware and have not discussed whether their appointed CEO is up to par to do this?

Can you name me any employer who hired a full-time employee and is happy to pay them full-time salary while the employee deceives them for financial gain and works part-time and/or outputs the minimum amount of work hoping not to get fired?

If you believe you can do more work, go freelancing/contracting/self-employed.