It's a funny thing, this whataboutery (or wharaboutery as I originally typed it by accident, but is suitably scouse appropriate).
People use it to justify their own position, in this case, saying people who buy official merch/Nike are hypocrites, and if they don't wish to be branded as such, don't buy from the club's official sponsors. But at no point does said poster acknowledge the moral vacuum that exists within their own position.
Basically, it comes down to, "I love blood money, and you can't criticize me for that unless you yourself are whiter than white. And even then, it won't change my mind. Give me the journalist murderers."
For a fanbase that frequently suffers despicable chants of "murderers!" from rival fans, for some to want to be associated with actual murderers is very strange.