Dandelions actually do important work for your lawn. They break up the hardened soil to make the ground softer for the grass to grow in. Letting dandelions grow will lead to a more beautiful lawn.
I wonder is it something specific to the USA or in other countries people are obseessing over nit having them in the lawn?
I'm in France and every though WE are far from having wild urban meadow or meadow at all, I've never heard of people and HOA complaining about dandelion before learning nolawn mouvement on the internet.
Dandelion greens are really good for you. Plus as others have noted monoculture lawns are pretty bad for the environment. Better than impermeable surfaces but still not great.
You can make Dandelion wine, coffee, dandelion salve, dandelion syrup, dye your clothes and eat them, to mention a few uses. - maybe he should sell them.
I fucking hate dandelions, I hate herbicides a shit ton more though. I planted clover and other ground over to compete with the dandelions and to feed the bees. My husband and I go out picking dandelions any day it's not raining and we see yellow in the yard. It's kinda fun to see who can get the longest thickest root 😉
if you're letting your dandelions flower, you should remove them when they go to seed. if they seed your neighbor's lawns, your neighbors are probably going to use pesticides that are going to be flushed into your local water table