I do believe writing for the Hubpages is entertaining for both the writer, and the reader. I love writing, and having an audience that is interested in the topics I write. I believe, even if a writer gets paid, they still have to be entertained to do it. You can compare it to an artist. An artist got started painting, because he liked to paint.
Now as far as being entertaining for the readers: it doesn’t matter what the topic is, people will only read what entertains them. A person is not going to read something because they are not interested in the topic. A person will read something because they are interested in the topic.
To sum up the answer to your question, yes, it is for entertainment purposes (in my opinion).