No one is arguing that that isn't an OPINION. But simply having an opinion on a religious topic does not make you religious.
Having an opinion on any religious topic means you have some sort of religious identity. The combination of your opinions on religious matters can be used to determine what religion your views align with the most. You don't need to be an "official member" or "belong to" that religion or any other in order to discern which of your beliefs line up with those of which religion. If, for example, you say you don't believe in god, that lines up most with an atheist religion. That doesn't necessarily mean you are atheist, but simply that you have one belief that lines up with those of atheists. The combination of all of your religious opinions will tell you what religion you most identify with.
My point in all of this is that you can't offer an opinion (or more than one) on a religious matter and then claim to also have no religious identity, because one can be discerned from your opinion. So you are religious if you have an opinion, whether you want to think of yourself that way or not.
If Bill says, "I hate all religions. I think they are terrible, hateful, murderous, insane, idiot collectors. I wish I could kill everyone in every religion and then **** on their graves"
That is a religious subject. Bill has an opinion on that religious subject. But no sane person would consider Bill religious.
The problem is you are thinking of "religious" in the way you are conditioned to think of it rather than simply using the term for what it is.
Bill's opinion is religious, and therefore he has a religious viewpoint, and I'm sure there are some religions which line up with this viewpoint that his religious identity (the part of it we know, which you describe here) would line up with. It could be said that he is of that religion, even if he personally doesn't want to identify with any religion.
There is a difference between what you identify with, belong to, or are a member of and what your opinions show your religious identity to be. They are often the same, but you can obviously express opinions which don't line up with anything that has to do with the religion you claim to be (people do it all the time).
My point is that your real religious identity is the sum of your religious opinions and NOT what you claim to be (because I can claim to be anything, but my honest opinions will show how I really feel).