I take the view that if you can afford it and enjoy it, why shouldn't you have nice gear? There's no need to "justify" by claiming that your gig (or heaven forbid, your technical prowess!) requires it, or that no one will take you seriously with cheap gear (as others have said, no one else besides other bass players really cares!). It's a mistake to convince yourself that expensive gear will make you a better player, as well. But I personally just enjoy playing nice instruments, and since I'm doing this mostly for enjoyment anyway, why shouldn't I play an instrument that will maximize my enjoyment?