They were wrong in teaching it to children, but I don't think many people would want to see their significant other holding hands with someone else. There is a lot of wisdom in ancient religions but it's often wielded by less-than-capable people.
I don't understand this idea that a partner holding hands with a non-partner is inherently threatening or uncomfortable. On the contrary, seeing my partner being comfortable and able to express intimacy is a strong positive signal of their ability to form a secure attachment with me and other people dear to me.