As an anthropologist working in a STEM field this whole thread amuses me greatly.
1. Obviously on some level scientific facts are social constructs. Science is a human social enterprise which seeks to create 'facts' to best describe the natural world. Sometimes these facts are right, sometimes they eventually get proven wrong and superceded by better facts. Sometimes (as with Newtonian physics), they retain great usefulness but do not accurately portray reality. Sometimes, they do seem to be perfect descriptions of reality. Great. Any statement is still a social construct whether right or wrong.
2. It is especially important to know this as a scientist. All ideas can be challenged, you simply can't do science if you start treating facts as holy cows, that, in itself, is profoundly unscientific. That does not mean you throw everything out because it's 'all made up'. Everything stands or falls on the basis of evidence.
3. Take the case of Cecilia Payne-Gaposchkin for instance. She was the first to discover that the sun was primarily made of hydrogen and helium. The evidence was clear, but she was persuaded not to publish this as she was a student, a woman, and this was at odds with general scientific belief at the time. This 'information' did not become a scientific 'fact' until 4 years later when it was eventually discovered again by a senior male researcher. Now, whatever you think of the process by which research becomes accepted as fact, it not apolitical or asocial.
4. You don't have to agree with a concept to learn about it! This isn't something a professor just 'made up'. We're taking about social constructivism, postmodernism, and fundamental tenets of STS. Any lecturer would be entirely remiss to leave out massive and influential philosophical movements in a class such as this just because some people don't like the idea. There are huge, often contradictory, schools of thought in a subject area that straddles everything from genetics and neuroscience, to politics and philosophy. You don't just leave stuff out because it's no longer fashionable. If you want to disagree with something you should do so from an informed perspective, not one of ignorance.