The html_input field type shows actual HTML when shown in List View. This is expected behavior, but is not user friendly.

1. Open incident.do.
2. Click Personalize > Form Layout.
3. Create a new field of type HTML.
4. Add some HTML into the field.
5. View the record from List View.
   The actual HTML values are in the form.

There are no plans to change this behavior in any future release. HTML fields are designed to be used in forms; not in list view.
Displaying HTML content in list view may not add more value, because only limited text can be shown in the table cell.