To review or not to review ... a very difficult question

A sort of blog!I am not doing any reviews at the moment because I am confused as to the on-line criteria for judging a book and would love some guidelines.
My background is mainstream/traditional. My children's books have followed this route, the criteria for success being paperback sales and acceptance by the establishment. Not reviews because it's rare for young children to write reviews. So my attitudes and judgements tend to be mainstream and unfortunately somewhat old-fashioned.
The rules I apply to all books, whether traditionally published or not, are broken into 4 categories: presentation, linguistic ability, (grammar and style), a credible and cohesive story line, and general enjoyment.
Should I continue in this way? Should I judge an ebook at the same level as a paperback traditionally published?I honestly don't know. For instance, if the typesetting is poor, do I ignore and still give 4* because the story is okay? If sentences and grammar leave a lot to be desired, what then? If the story meanders ...?
What are the main aims of our writing to self publish? Are we just writing for fun and want to be judged on the enjoyment factor? Or are we seeking to be judged on the same platform as books from a traditional publisher?
There remains a vast level of snobbery in the book world. However, what is becoming apparent is that there are two book worlds which don't meet except occasionally. Traditional or mainstream with paperback as the main focus or self-published ebooks on line. Which one are we wanting to belong?
If we want to be accepted mainstream by the public at large, society of author, teachers, booksellers, etc. we have to comply with the four criteria I stated above. If we only seek an on-line presence and readers en mass, are these criteria still relevant?
And this is my problem ... when reading a book, I don't know what the author is seeking to achieve with his/her writing and therefore I don't know how to judge it.