You didn't do very much research then.....
They are talking about the knives not being one solid piece in reference to the locks on folders and the fact they fold or as said already broken.
That said there is nothing in using a knife that a fixed blade can't do as well or better then a folder generally speaking, that is keeping things apples to apples as in comparable blade shapes etc.
The only thing that a folder does better is fold to make them fit in a pocket easier, other than that there are zero advantages of a folder over a fixed blade.
That's not even a debatable subject topic.
It's one of those DUH... HUH..... WHAT..... topics.