Every band has a shelf life; BB had finally expired.
We always felt excluded in many ways never reaching......
I've broken the snippet into two separate lines for the sake of discussion.
Narrative is subtle.
The verb in the first clause is aphoristic. "Every band has". Such general wisdom is delivered in present tense in English. "What goes around comes around."
In the second clause, BB had finally expired, the past perfect is not only acceptable, it's good, better, IMO, than your suggested "BB finally expired", because the past perfect is an explicit continuation of that aphoristic perspective: BB had reached the point that every band sooner or later reaches. A simple past tense would be asyndeton, leaving the connection of the two statements implicit.
The statement delivered in the simple past in the second line (we always felt) is not a part of that wise perspective; it's how they felt...and so the tense shifts to simple past.
To say instead "We had always felt excluded" would imply that at some point they had stopped feeling excluded, because the past perfect is used for actions completed in the past.
We had always jumped directly into the chilly waters the second our
boat dropped anchor off Amity Island's southern shore. But the summer
of the great white shark turned us into landlubbers.