Their website states they search "<language> programming", so anything programming related would be counted - including content about Ada Lovelace. And the American Dental Association, which also comes up on Google when I use this query.
TIOBE also includes SQL because technically SQL is Turing complete and that's the criterion for inclusion on the index, ignoring that this isn't the real reason people are using SQL.
The more I think about this index the more my head hurts.