Living in Houston all my life, we have always done this. I expect that most people who have lived here long enough to go through a hurricane or tropical storm disaster do keep a hurricane kit stocked and ready to go with water, food, medical supplies and pet supplies in the event that we do need to make a run for it.
Texas was built by neighbor helping neighbor and inviting newcomers to become one of us. We went through something like this in 2001 with the tropical storm that innundated Houston with as much as 35 inches of rain in some areas. Lots of people found themselves flooded and needing rescue. Our friends in Louisiana provided assistance in our time of need.
We're not perfect in Texas and we do have our faults. One of them is that we do not suffer fools lightly.
Unlike you, I have not lived in Houston all my life but I have never been in such a friendly city. Strangers on the street/stores actually smile at you. Most drivers allow you to merge. Little things like that. It does not surprise me at all that Houstonians have opened their hearts to the evacuees. The NYT would never recognize the dynamic yet human heartbeat of Houston.