First, as an entertainer, all bassists should recognize that the normal person in the audience primarily hears the vocals. So, all bassists should try, within their capabilities, to contribute to the singing.
Next, if you are blessed with a great voice, it would be a shame to waste it. The bass line is a secondary supportive function. I say, if you can sing, go for it, and the bass lines will fall in where they may.
In my own case, I was not born with a significant range capability. But, I figure that Billie Holiday had less then an octave of useful range (at least that's what I heard) and look what she did with it. So, I just pick out the tunes that people know that are within my range. I guess it was about ten years ago that I figured I would get more mileage out of learning to sing vs playing more notes. And although I don't normally take the lead vox position, I do have about 40 - 45 tunes that I can do and contribute with, and if the front person wigs out, I can carry the gig if need be.
Finally, it has been my experience that doing at least some singing has some other advantages; among them, it helps you as a player hear the whole mix, you get to sing some really great songs, and it helps you hear how to fit bass lines into the vocals; because as I said earlier, the vocals are the main thing people listen for. So, there is significant synergy, and learning to sing some lead parts will actually make you a much better and more aware bass player.
IME/O
GL to all.