Facebook should never have facilitated this level of data collection for any campaign, but characterizing the current anger at Facebook as media-driven favoritism is Internet Research Agency level trolling.
That of course doesn't conclude that liberals or what you prescribe to liberals is correct. But there were still significant differences between the reelection of Obama, a sitting president who won with a lesser margin than expected and Trump, an outsider not only to politics but the republican party, who won by a slim margin targeting certain fringe issues and key states.
Further, the "only angry because it's President Trump" narrative ignores the fact that there has been a rising tide of concern and pushback on data collection and customer surveillance business models. The fact that Trump's campaign was involved may have been a catalyst, but a catalyst cannot operate in a vacuum, it requires very specific preconditions, ready and primed for that spark. And the longer it builds, the smaller the spark needs to be.