Critique can be taken and used in many different ways. It can also be framed in many different ways.
I'm thinking about this partly because I wrote something critical about a published author on this blog the other day, and I saw that someone had found my post on the basis of searching for the author's name. I looked back at what I had written, and felt like I had come across as ripping an author that I didn't intend to rip. I did intend to say that I saw somethings differently, but that is not a rip, it's just a different perspective.
Personally, I don't like to get locked up in arguments about what is true or not, because what we believe is so wrapped up in a whole interplay of ideas that trying to disentangle one part of the perspective that it seems almost meaningless to try and debate the one part with respect to some abstract "truth". Instead, I like to think about the situation with respect to differing perspectives that we can use to help understand a situation.
When we receive a critique, it can be difficult, because critiques usually rely on a perspective that doesn't match our own, which is their value. That difference of opinion, however, can feel like a disagreement, or an implicit denigration of our position (or sometimes an explicit denigration).
I like to try to separate the critique from myself by thinking about what the interests of the critic are and to try and understand what perspective generated the critique, and what aspects of that perspective are useful for me in developing my work. That ain't easy, though.
Sometimes critique is a personal attack. That's unfortunate. But then many unfortunate situations abound in this world.
But often critique of a work or a set of ideas espoused by a person is not an attack, but is, instead, an attempt to share a new perspective.
In the blog posting where I critiqued the published work, my intention was not at all to critique that work, but rather I was using that critique to help explicate a position I held. It was an attempt to share my perspective. Using the other author as a foil was a stepping stone in that direction because the other author used some ideas that provided a foundation from which I could work.