I could rephrase it that way and the answer would still be the same: How many concerts have you witnessed where a
BASS PLAYING member of the audience said after the gig: "Man, I really missed the low B of the bass player!"?
The B string concept is inherently flawed because I have yet to encounter a B string whose harmonics don't go ape when you play it in the upper register. A 5 string bass is to a 4 string bass not what the low E of a four string bass would be to a short scale bass lacking the E string. And 34" is not the right scale for B either, but any larger scale sacrifices D string flexibility which is already at a tension peak with a reg long scale and sounds better in lower scales. You can't really hear the note that is deeper than a low D either, especially non-musicians can't. And when it comes to focus of sound any cheap synth can cream you into the ground, how depressing.
But for the record: Everyone may own and play as many fivers as they want (unelegant as they are and who heard of stringed instruments with an uneven number of strings!). Just don't tell me that it is mandatory in more than 10% of the parts of - at best 1% - of todays popular music.
I just don't see what there is to get excited about five halfnotes more, three of which are barely audible in the grand scheme of things and the ability to play vertically rather than horizontally, IIRC the Fender V failed with that "groundbreaking concept" royally. So what you are left with is a hugely invasive step (all 5ers sound more sluggish than their counterpart 4s for the additional wood mass unless the 4 stringer has a too skimpy neck in which case the 5er version lends it some welcome mass) for two audible halfnotes more. No, I don't see that in the same league of change and musical development as the electric bass was to the double bass in popular music, not by an XXL scale stretch. Listen to a Glenn Miller tune with a double bass and an electric bass and you'll know what I mean.
I have about a dozen fivers, some of them are even excellent basses (like the Status V Stealth II whose sustain just doesn't stop, yet is utterly snappy due to the one piece graphite body and neck) and playing them once in a while is a guilty pleasure because drummers (you know how they don't really listen to tonal notes ...
) and similar life forms like them, but mandatory? Naw ...