I think most people still confuse "rap" with "hip-hop". The apples to fruit comment above, in fact, fits that as an analogy far better than fitting that Hip-Hop isn't music. Rap is something you do over a beat. Hip-hop is the entire culture associated with the musical genre of the same name. As for the genre of Hip-Hop music, it can incorporate Ambient Hip-Hop tracks like Fatboy Slim or DJ Shadow's work, all the way to Glam/Bling rap, which is what most of the detractors see as such a devastatingly bad image to Hip-Hop. But you need to look at Hip-Hop like every other genre and culture from a musical standpoint to understand the subtleties.
Rock music began as an offshoot of Blues which was an offshoot of something else, ad infinitum. All music has it's roots someplace else. And, strangely enough, the newer the music, generally, the less it is "accepted" by those of older or different genres. Hip-hop has only been recognized since the early 80's as being it's own genre, though one could argue that it's roots could stretch all the way to some spoken word tracks from the 20's, so it is fairly new in the scheme of things. And it has been loathed by critics since it's inception, but this is no different than other "experimental" or socially unacceptable musics.
When Elvis first began his trek to stardom he along with other classic rock and roll stars, such as Buddy Holly, were seen as socially and morally unacceptable, as little more than racy lyrical content and horrific musicianship at best, but at worst Rock and Roll was described as not even being music. Rock morphed into Metal, which also was first described as not being music. Techno, first described as not being music. Worse than that, musicians who played "analog' instruments saw the digital underpinning of techno as unnatural and nonmusical, simple even. Every genre can accuse another genre of being "simple".
To usurp the earlier statement about using samples being simple, "How hard can it be to spin two records and mix together a song?" Which is exactly what DJ's in many techno genres do...but I dare you to claim it's easy to do. Also, "How hard can it be to program a computer to produce saw tones and create techno music?" Which is the other aspect of techno musicianship and also not easily accomplished. "How hard can it be to play the same 3 power chords and growl into a stage mic about demons and angels?" Heavy metal music. Also not easy or simple. "How hard can it be to write a song about a ford pickup truck and a hound dog on the Texas plains?" Country music. The point is that if you don't have experience in the genre, you might think it's simple but if you take the time to try and reproduce the music, you'd note how hard it really is to create a quality track.
The problem is that, yes, all genres have their one-hit wonders and their bad apples who make the genre look like trash. I, personally, don't like bling rap at all. Lil Flip and Mike Jones made Texas look like trash, in my opinion. But they also make money and that's what their goal was, so I won't begrudge them that. But judging all of hip-hop on that? It's like judging all of techno based on Sandstorm by Darude, the most overplayed POS song I ever heard come from any genre of Techno. Or all of Heavy Metal based on Marilyn Manson, which had some of the simplest lyrics and musical numbers ever, but everyone loved him because he was outrageous.
The list can go on and on. The fact remains, if you don't like hip-hop, then that's great for you. I don't like country. But I am NOT searching out country songs online and sending messages to their singers saying "COUNTRY SUXX0RS P3n1S an so do u!!!!" But some music on NG gets that type of review, alot of it in the Hip-Hop genre which is sad really. But that's how it will be until some new musical form reaches the same status as Hip-Hop and everyone can hate on it for awhile. So the circle has gone since music began. I guarantee someone listening to ragtime in the 20's was busy saying "That devilish swing music, making people dance!!! How apalling!"