80,000 Hours is explicitly focused on maximizing social good, often by advising people on what career will maximize their "earning to give" potential. That is, earning a lot of money to donate to an effective charity (e.g. high rated charities on GiveWell).
Because of this, their analyses tend to look different than it would if it was optimizing towards a risk-adverse individual maximizing personal utility.
The justification for looking at expected value (averages) is expanded on here: http://80000hours.org/blog/12-salary-or-startup-how-do-goode...