Should I even bother to practice the low B? I have a Yamaha 381 so it has the low B foot and I can get a pretty decent low B but what is the point since there is very little chance that I will ever see it written in music.

yes it is very important to practice highnotes as WELL AS THE LOW NOTES
there are many flute parts that read in a low register so it is important you know how to play them all

I also agree that you should practice in all registers, even though you prob won't use the B very often...

yes, but when u do play it, you want it to sound good

Shouldn't you be practising scales from Low B?

If you practice beyond your normal range, you'll be better able to do the normal notes. You might not play a low B very often, but it'll help you get low C out much better.