I wonder how many of them have had their services suspended and the reason for 11?
I think its aimed at those who run an advertised trade business, like a plumber, builder etc. If they were to complain to BT about their service, then it could be suspended, as a last resort. I suspect many trade people are going to have some form of business grade account with a provider, especially if they need to keep the same phone number.
Online sellers on eBay etc, are not likely to be affected.
In the case of @DanM92 , the requirement for a static IP address is the issue, irrespective of any business usage.