The short answer is that it’s possible to hold individual beliefs without those being a worldview, or at least a worldview that you accept with certainty. I hope my points below clears up some misconceptions.
Let me start off by referencing the viewpoint, i.e. agnosticism, before I address any points about individual people who claim to hold the agnostic viewpoint. First, according to Thomas Huxley, agnosticism has no worldview, creeds, or tenets, except one, which is to avoid dogmatism or to not hold any certainty in matters (metaphysics) that are not scientifically nor logically validated. Agnosticism as a behavior or expression would simply involve an approach, way of thinking, arguing/reasoning that avoids dogmatism. Two ways I’ve gone about sustaining my agnosticism is by approaching intellectual matters as if I know nothing about it (starting from scratch or suspending judgement) so as to avoid preconceived beliefs, biases, etc and building from there or by starting out with what I know for sure and progressing from there. Probably no different than the scientific approach which should also be devoid of dogmatism.
As for followers (for a lack of better word) of agnosticism, it’s true that they may hold worldviews if they are not completely or consistently agnostic on every matter, especially when coming from backgrounds where a worldview was instilled in them from a young age. However, an agnostic should not hold any certainty in any of his views unless it can be backed by science and/or logic, so therefore there’s no worldview that I accept as being true. I’ve been able to do this at least when it comes to the issue of God and spirituality.
Compare my point to Christians who always hold that their worldview is true or atheists who do the same when they mix in their worldview with science or make science itself into a worldview.