That people care about something that you can't relate to more than their own lives isn't a sign of stupidity, it's a sign of other people having different values than you.
Lack of intelligence and or sensibility has nothing to do with this, it is decision based on the relationship I share with my dogs, I am their 'pack leader', a bond created from their unconditional trust and love. Like any good relationship to survive, their needs to be a strong mutual commitment, in this case, they would unquestionable give their lives to protect their pack and myself. From the comfort of safe reflection, I truly believe I would do the same for them. Besides my immediate family and my dogs, I am not sure I can say I would make that sacrifice for anyone else.
You are equating your own worth to that of your animals, based on a role they've instinctly assigned to you.
Forgive me, but I'd appreciate if you'd spare me any further explanations and attempts at justifications.
Your grandiose sense of self-worth has retarded your capacity for understanding to such a degree that it compels you to criticise someone else's decision to sacrifice themselves for other beings they love, yes, even non human ones. Have you ever loved? But yes, I forgive you.
Your unjust accusation of egotism still presupposes equal worth of humans and pets. This is wrong, regardless of your emotional attachment to yours.
From a purely economical point of view, you may claim that things have only the value you ascribe to them. But I believe in intrinsic, objective worth.
One man's teddy bear is another's broken toy. A person's life, however, is non-negotiable.