I think there was an effort in the past to make sure it’s a family show and disconnect The Doctor from the more mature parts of the whoniverse. Maybe the changes in production and, maybe, the realization adults are too obsessed with it create new avenues for money making creativity.
It was originally an edutainment show for history and science, and had a strict policy of no kissing, no bad language, and no bloody violence. They still keep to the last two.