1. Some ISPs have provisions separating home use and business use and are priced accordingly.
2. Some ISPs (possibly overlapping 1. or not) explicitly disallow hosting of any service on their Internet plans that they categorize for home use in their Terms of Service.
Hosting a personal blog is beyond the reach of a lot of people. I feel like a large number of the general public wouldn't really ever have it occur to them as an idea in the first place, and of those that do a surprisingly large number might find it too complex for them.
I doubt ISPs would easily cut someone's home internet off. Is there precedent for that?