While I agree that disdain is not the right reaction, neither is misdescribing what these disciplines are. And the most important fact about them is: they are not sciences.

We do not have a science of how people work, how groups of people work, how collective action works. Dealing with people is an art. It requires applying non-repeatable human judgments to non-repeatable human situations, and doing so constantly, day after day, year after year, realizing that there is never going to be a stable state of things, there is never going to be a time when you have dealt with all the conflicts and solved all the problems and can sit back and relax.

Engineers are understandably uncomfortable with such a situation because it goes against everything we (I say "we" because I'm an engineer myself) are taught. We are taught to engineer solutions to problems, solutions that keep working, if not forever, at least for a long enough time that we aren't constantly having to manage them. A well built bridge does not require constant engineer attention once it is finished.

But there is no such thing when it comes to humans and human relationships. They do require constant attention in order to survive and flourish. But we have no science of how to do that, the way we have a science of how to build bridges. All we have is our fallible human judgment, and if we're lucky, some rules of thumb that, while they aren't science, are hopefully better than nothing. Unfortunately, I think what rules of thumb we have have been mostly ignored in the process of building systems like social media.