I can't speak for most people (obviously) but I play the B string above the 5th fret more than I do below.
My rock band plays some modern rock songs from Nickelback, 3 Doors Down, etc, where I frequent the nether region ("LoLo Land"?), and I occasionally build octaves off the lowest notes for emphasis ("Comfortably Numb" by Pink Floyd sounds pretty awesome if you add just the right amount of low B underneath).
OTOH, even with classic Motown where I stay inside 4 string territory, I play a lot of songs starting above the 5th fret, including the B string, so I can put more range under my fretting hand.
I set the low B so it's usable up to the 12th fret, and if I'm not lazy I can get even more range from it.