A bad property of single elimination is that it allows for negative voting, i.e. voting against candidates you do not like. So while first past the post is bad it is in my opinion still better than single elimination. More sensible methods include having a two or three round voting (where you eliminate candidates after eahc round) and prefferential voting (where you rank your favourite candidates).
I think preferrential voting would be best, but that would be a one-time vote and not require you to visit the website every day to make a new vote. Plus, more people can relate to a single elimination bracket system trying to emulate a sport's playoff.
It's good to see CK being put up against mainstream titles, it shows how far Paradox games have come over the years for CK2 to be released as a finished product and accessible to new players. However, I'm glad it's not getting too much attention; once games with a lot of depth become too popular they tend to be dumbed down to appease the casual players.