In Mexico one distributes the wealth, 5 pesos to the parking attendant, 5 pesos to the kid that bags your groceries
There have been times when I didn't want to roam around the store while Sue did the shopping so I sat in the car and watched the parking lot guys. Here is my take.....
1 - they help you find a parking space and stop traffic to help you get in
2 - they watch the cars so nobody messes with them
3 - they pick up litter around the parking lot and try to keep it neat and clean
4 - they help you load your groceries into your car - they will wheel your cart out for you and take it back to the store for you
5 - they help you back out of your space and will stop traffic to make sure you can back safely
6 - in some cases they will wash your car - or at least your windows for a very reasonable fee
7 - sometimes they have cardboard to cover your windshield so the Sun doesn't cause your car to overheat
We see the Mexicans tip them so we tip them too - they do provided a service and they don's just stand around begging - they work for the few pesos we give them
The grocery baggers are usually kids working after school for a little spending money or to save up for future education - we always tip them too.
As far as the Ag Check spray in the Baja - it has been there forever and will probably always be there - it may not work but the effort is there to protect the Ag products we all like to eat - no bugs means good food - we like it.