This is going to be hard to explaine, but I'll try.
Ever see those photos of guys that all look kinda alike, spiky hair, duck lips, red plastic cup, peace signs, polo shirts with popped collars, bad tans, and shitty poses?
Those, my friend, are douchebags. The brands mentioned are those typically worn by the common douchebag in the wild. There are several other things they have in common (Ed Hardy gear, for one), but they all generally have the same tell tale markers.
Most people don't like them because they insist Jersy Shore is a valid way of life, that they think they are better then everyone else not in their lifestyle, and well as generally possessing of grating personalities (as well as duck lips. What the Hell is up with those?!)'.