You are completely right.

But...is 1366x768 really the dominant resolution right now, even with the emergence of Apple as a dominant PC maker?

On my site, the top 3 resolutions are as follows:

    1. 1440x900
    2. 1600x900
    3. 1920x1080

After that a mishmash of phone & tablet resolutions come before 1366x768.