If I didn’t specifically opt in to receiving marketing emails (and no, failing to opt out is not the same), they are spam. I’ve never heard anyone say “I’m sure glad this company added me to their email list without my request.”

The fact that you happen to work on a mailing list product does not change that reality.

Useless is in the eye of the recipient. The sender doesn't get a vote.

And guess who's the beholder of your spam...