You don’t need to lose respect for people who are brainwashed by capitalism. They don’t know better because it’s normalised for them all the time. If you berate them, it won’t make them change their ways or see that they’re doing harm.

Mailing people out of the blue is probably a good way to get new customers. How else will people know? SEO is always tricky, advertisements are often blocked, calling a company or sending some mails might get better results. However, twelve mails is clearly overdoing it and there should be a functioning opt out button even out of those mails.

I guess a better way would be to go to conferences of your target demographic, but that would require effort.