Because TV is so simultaneously personal (it exists inside your home) and so utterly universal (it exists inside everyone's home), people care about it with an atypical brand of conversational ferocity — they take it more personally than other forms of art, and they immediately feel comfortable speaking from a position of expertise. They develop loyalties to certain characters and feel offended when those loyalties are disparaged.
This is what makes arguing about these particular shows so intense and satisfying — even though most serious TV watchers enjoy (or at least appreciate) all four, they habitually feel a greater internal obligation to advocate the superiority of whichever title they love most. As a result, you hear people making damning, melodramatic criticisms of TV shows they ostensibly like.
You hear a lot of sentences that begin, "I love Mad Men, but …" or "The first two seasons of The Sopranos were great, but …" And whatever follows that "but" is inevitably crazy and hyperspecific. This is especially true among people who prefer The Wire. There's never been a more obstinate fan base than that of The Wire; it's a secular cult that refuses to accept any argument that doesn't classify The Wire as the greatest artistic endeavor in television history.
It's almost as if these people secretly believe this show actually happened, and that criticizing the storyline is like mocking an episode of Frontline. This was not a documentary about Baltimore: Wallace is not alive and playing high school football in Texas, Stringer Bell was not reincarnated as a Pennsylvania paper salesman, and you are not qualified to lecture on inner-city education because you own Season 4 on DVD. The citizens on that show were nonexistent composites, and the events you watched did not occur.
As a society, we must learn to accept this.