Of course a "zombie apocalypse" wouldn't go down like The Walking Dead
, but that's not really the point. It's been a problem with the genre as soon as it became something that was transferred from infected to uninfected, as opposed to Night of the Living Dead
where it was implied that people who died for any reason whatsoever would become reanimated.
The viral concept caught on later, presumably because the public finds it more plausible, even if it really isn't. I recall seeing a number of articles in the past few years making the same point about a zombie virus. It would certainly disrupt things, but not nearly on the level depicted in most zombie movies or books.
You could always write the virus as airborne, but as soon as you do that, you've got a different kind of story.
When Kirkman conceived the book, it wasn't out of a desire to portray what would actually happen in the case of a zombie outbreak. It was to explore the idea of what would happen if one were to keep a camera on the characters in a zombie movie after the credits have rolled. As a result, he has to stick with the genre as it's been established.
As for this season, I liked it overall, but there were problems for me, especially with the CDC storyline. I wish they stuck more closely to the comics. Not because I'm a stickler for adhering to the original work, but because I think the exposition of the last two eps is a mistake.