I'd venture to say that if you aren't noticing that your pet is dead 90% of the time when it dies, you aren't paying nearly enough attention and/or not playing the class well. I notice when my pet dies immediately. I'm constantly micro-managing the pet cooldowns and AI modes in order to make sure it is available to do what I want, when I want.
It is like saying you wouldn't notice if Bio 2, Miasma and Bio went missing from your toolbars. Of course you would. (should)
Blows my mind how people could not notice their pet is missing.