Because its irrelevent and this is the first time that anybody has ever made a big deal about a 5 week January.
They have existed before and people have compared years with a 5 week January to years with a 4 week January and its never been an issue.
All of a sudden its a huge issue because it puts their console at a "disadvantage"
You are free to bring that up in the other comparison threads. But you cannot reply to a question about why it is irrelevant by saying “because it is irrelevant”.