Why? Because people are sad? Look, their entire LIVES got turned upside down. Of course they're sad. But it doesn't change the fact that these shelters are designed for people, and the limited resources they have to sustain themselves need to be devoted to them and them alone.
but only people who got there by unofficial means got to take their pets.
Translate: only people who paid attention to the evacuation warnings got to take their pets.
It must have been doubly heart-breaking for those who were forced to leave pets behind, to arrive in Houston and discover that they would have been welcome there.
I'm sure it would be. Category 4/5 hurricanes are a real pain in the butt, aren't they?
One reason that people don't evacuate for a storm is because they can't take their pets with them. For every animal a person has, there is a 50% less likelihood of them evacuating. Most people don't see their dogs or cats as material posessions and even an emergency won't change that. It doesn't take much to accomodate pets if they are in crates and the owners look after them. Most counties in FL are starting to have pet friendly shelters because of this.