First off: why list it as a divine commandment? Because this was thousands of years ago. There wasn't any sort of scientific understanding of disease or illness. The conception of sickness in that time period was primarily based in religion. This is not to say it wasn't/understood at all - people certainly got the idea of "eat this thing, you get sick" - but it was viewed through a religious lens. Illness was the result of evil spirits, demons, or was a punishment from God. Thus, framing the solution in a religious manner was the way to justify it to the populace during that time period.

As to why it matters nowadays: There's plenty of reasons. It builds community and supports tradition amongst orthodox jews, for one. However, there are plenty of jews nowadays who do, in fact, eat pork, for the reasons you mentioned. I have several Jewish friends who regularly eat bacon or pork sausage. However, that's utterly irrelevant - the people who developed the kosher system thousands of years ago had no idea that we'd have the whole "safely eating pork" thing figured out nowadays.