They make no sense in their argument against me...?

So I told my parents I was transferring to the local Community College to get my EMT-P and they were thrilled beyond all belief. I also told them that before I started work I wanted to serve my country as a Navy Corpsman and they screamed and yelled for days about mindless bullcrap that sounds like hippie propaganda from the 60's. I mean what's the difference, one carries a weapon and the other doesn't? Not like I would be in any more danger working with the Fire Department here than serving as a corpsman with the Navy or Fleet Marine Force. I live in a city with a pretty high violent crime rate, lots of severe weather, and other crap that a fireman or paramedic could be exposed to. In fact I would probably say it's more dangerous than being FMF. I don't understand their mindset at all and have no idea how to deal with it.