As someone said, for him to rid his page of a handful of Tattle followers (i.e. the ones he thinks have no identifying information - photo or name), he'd have to delete his account and start from scratch. That's a lot of work for little reward and doesn't bode well for selling books or launching Twittle. He'll then not organically attract the thousands of followers he seems to crave. He's not a celebrity or brand.
Harshly put, he's just a guy with cancer, among a sea of similar unfortunate stories; his isn't unique nor compelling enough to grow the numbers that he seeks.
I can't help but think about the people with cancer who I follow. Small accounts, not nearly the high numbers as BB. They all quietly tell (or told) their stories, share information and experiences without fanfare or selling books, merch, or affiliate links. One woman wanted her legacy to be information about colorectal cancer and her Instagram is incredible - she helped people find trials, work around insurance barriers, get financial help. Her husband still posts. Another just posted about Medicare and younger cancer patients.
Every cancer account is different and some need money because of lost jobs and treatment costs. I get that. I just prefer transparency when asking followers to buy their self-published book, sweatshirt, Invisalign, Hello Fresh, or air fryer on Amazon.