(I added some more links in the above post.)
If they don't believe in God, why do they insist on framing themselves by theistic beliefs?
They do not consider those beliefs to be theistic, I guess.
The problem of course is that atheism is an empty bucket, becoming an atheist means you have nothing to follow.
This is not true - in the sense that one cannot but have some position. Atheism theoretically claims to have "no beliefs in God", but practically, this is impossible.
From Wiki:
According to Paul van Buren, a Death of God theologian, the word God itself is “either meaningless or misleading” [1]. He contends that it is impossible to think about God. Van Buren says that
“we cannot identify anything which will count for or against the truth of our statements concerning ‘God’” [1].
“We cannot identify anything which will count for or against the truth of our statements concerning ‘God’”. -- this is a position.
I myself am struggling with this. I'll have to ask for some help on this.
So they simply make do with whats available from the religion they no longer subscribe to and claim it is an "identity". And thats fine, but its disingenuous to say I'm a cultural Jew or I'm a cultural Christian when their core beliefs are unpalatable to you but you still want to enjoy the benefits that go with belonging to the community.
These people are hijacking religion and pretending to be a part of the community, but essentially they are just people who have nothing else to call their own.
True. I think it comes down to common decency and philosophical skills.
Namely, I think the "death of God" movement and related have brought the philosophical questions concerning the nature of God and belief in God to a point where they could not answer them in a way that would satisfy them anymore, nor did they have the faith to put those questions aside as unimportant enough.
Peple in general have the tendency that when they reach the end of their wits in some matter, they declare the matter to be impossible to resolve, ever, by anyone, by any effort (like Van Buren above), or they declare the matter to be unimportant or irrelevant.
In my opinion, these are just impermanent positions, though, and that will shift in time.
In essence, there is an element of taking responsibility for one's philosophical reasoning as well, but it seems this is not as common as "taking responsibility for one's actions".