Your application of logic is not valid here, because "everything on the page matters" has not been given in a formal way, and you're cherry-picking one interpretation.
What if it is intended to mean something like:
∀x ∃u: onpage(x) → matters(x, u)
"For each element x, there is some user u, such that if x is on the page, it matters to u."
This is not contradicted by this version of "anything doesn't matter":
∃z ∃v: onpage(z) ∧ ¬ matters(z, v)
"There exist elements z for which there are users v, such that z is on the page, yet doesn't matter to v."
But is contradicted by a different version of "anything doesn't matter" like:
∃z ∀v : onpage(x) ∧ ¬ matters(z, v)
But you can easily find a person in the world who doesn't care about any aspect of something, let alone just one aspect of it. So what?
If we restrict x to just the universe of users who are interested in at least one thing on the page (i.e. who are actual users), and we have somehow ascertained that everything on the page is covered by at least one user in that set, then the claim holds. You need to supply actual evidence that there is an item which no user ("person interested in at least one thing") is interested in; just you not being interested in something isn't it.
What if it is intended to mean something like:
"For each element x, there is some user u, such that if x is on the page, it matters to u."This is not contradicted by this version of "anything doesn't matter":
"There exist elements z for which there are users v, such that z is on the page, yet doesn't matter to v."But is contradicted by a different version of "anything doesn't matter" like:
But you can easily find a person in the world who doesn't care about any aspect of something, let alone just one aspect of it. So what?If we restrict x to just the universe of users who are interested in at least one thing on the page (i.e. who are actual users), and we have somehow ascertained that everything on the page is covered by at least one user in that set, then the claim holds. You need to supply actual evidence that there is an item which no user ("person interested in at least one thing") is interested in; just you not being interested in something isn't it.