I've ridden my DH bike for my 30km one way commute to/from work and for multiple hour trail rides (along with using it for it's intended purpose), I've ridden my road bike on singletrack (again along with using it for it's intended purpose), and I've used my Blur 4x for shuttle trails, commuting, and trail riding...so...do these marketing terms actually matter?

Just ride the bike that best suits your trails and your riding style.