I agree with most of what you said, except the fact is, chargers are in fact quite expensive to install. Putting in a large number of them requires massive upgrades of the electrical service. Consider putting in 20, 30A chargers would require a ~800A-rated service (since all could be in service at the same time and you need some safety margin), vs the 200A service installed in the typical home. It's also hard to run them to spots far away in a parking lot, which ups the installation expense quite a lot.