There may be quite some feet to span from the stage to the mixer. For these distances you'd really need balanced signals or you may get a nice wash of additional noise to your bass sound.
Multi cables from the stage to the mixer are as far as I know always balanced in the first place, so you'd better feed it with a balanced signal.
I've asked this very question myself before. When I stick my bass directly in my mixer at home just to play a bit, I don't really bother about putting a DI in the chain. I just crack up the gain on the mixer a bit more. And that has worked fine for me for years.