I get SMS spam on Google Voice somewhat regularly, and occasionally also voice mail spam.
As for Google's concern with "bad actors", any search with "ebook" or "download" would tend to demonstrate that as long as they get their vig, Google is quite flexible on what constitutes a "bad actor".
I was shocked to get my first spam text in 3 years over the weekend. I was pretty surprised as my number is in plaintext on my blog, Facebook and is found with my name in Google searches. On the other hand, not a single human being other than my mother know my real mobile number and I get a spam text once a month.
That and a quick look at my Gmail Inbox/Spam-folder indicates that they're still winning the fight.
As for Google's concern with "bad actors", any search with "ebook" or "download" would tend to demonstrate that as long as they get their vig, Google is quite flexible on what constitutes a "bad actor".