The people who want privacy and the people you want to block are using the same services and techniques. That's why web firewalls block privacy focused browsers, why TOR exit nodes are blocked from bald the internet, why email providers block new domains, and why sign-up forms block burners ("aliases" as you might also call them).

You can accept privacy enhancing measures but doing so hurts your ability to filter spam and other abuse.

I use these burner email services all the time because nobody on the internet can be trusted. Especially not the ones that try to lure you in and pop up an email registration box at the very last minute.