Blocked isn't the same as Flagging.
Which is exactly what flagging an application as a Potentially Unwanted Program does. So Malwarebytes is doing EXACTLY what you want them to do.
Well, if that is the case, then maybe the rivals case against them is unwarranted.
However, the article doesn't specify that's it's just a once only 'flagging' of a suspicious program staying resident. The article just says 'Blocked' like Malwarebytes software is refusing to share the system with this competitor program above and beyond user interaction.