Everyone hates spam.
Ask someone for their cell phone number and they immediately think you will send them spam text messages.
Ask someone for their email address and they immediately think you will waste their time and send spam emails.
The internet gets clogged with spam emails every day. We directly track and block about 75% of email traffic every day because it's all spam.
Google has a dedicated department to fight "Web Spam" and all things that cause any type of digital interaction that will annoy people. This team helps to control the built in filters that block troublesome websites.
One of the things they watch out for are websites that plainly show email addresses. Freely posting your email address as email@example.com will invite spam. Malicious email com...