I have seen many people talking on this forum about Bing inexplicably deindexing their web services:
It's not that Microsoft "doesn't care", it is that their company in regards to Bing is a basket case to the point of criminality.
My business was suddenly "deindexed" by Bing aka put on a spam list for some unknown reason.
I messaged the Bing team and got this message back:
"Firstly, I am happy to provide you information that our product review group succeeded in removing the block of the site. After submitting your site to be reviewed the team has decided to lift the block. Please allow up to 2-3 weeks for your site to be crawled indexed and serving again.
I am unable to provide you the specifics of the block as our product review team does not share details of the block. However, I wish to help you with few links and help docs which will not only help in avoid blocks but also help you to rank better in the Bing index."
Nothing happened in regards to my site being available again in Bing; you could not type my brand name into Bing and find my site. So I sent another request and got this response back:
"Thank you for your patience. After further review, it appears that your site ******.com did not meet the standards set by Bing the last time it was crawled. Post a re-review, we confirm that your website continues to be in violation of our Webmaster Guidelines."
I changed nothing on my site in between these two responses.
If they want to rank my site down for key phrases that is their prerogative, but to deindex a business from a brandname like it has ceased trading and recommend competitors to use instead is criminal behaviour in my opinion.