I just answered that in the comment you're replying to. Let me itemize it for you and add another one:

    - I don't need more vertical space, it won't alleviate the need to scroll.
    - I can put two nicely sized windows side by side and say, watch a scrolling log file while writing code or working in a terminal.
    - My desk is wide, having wide monitors makes good use of the space available without needing as many monitors. If I had square monitors I would need 3 of them, instead I only need two 27" monitors to make good use of my desk space.

Again, my main point was not that I'm right and the other guy is wrong. My point is that it is personal preference and both are viable depending on what you prefer.