Is it okay to share nothing with your partner other than the bed?

It depends on what the partnership is really about. If it works for them, and life is good under those conditions, then I say it is perfectly fine. If either one isn't satisfied with that, then as betweenfatandfit says, it isn't a partnership, and the one who isn't happy with it should address the issue and if it can't be changed they should dissolve the relationship and move on.